At some point, it’s a decision every couple confronts. Try to sidestep it, and you’ll risk drab-looking, damaged hair or endless arguments that begin with “Did you finish my shampoo without telling me, again?!”

We’re talking, of course, about whether or not you and your mate share shampoo, conditioner and hair styling tools, or maintain your own. Merging his-and-hers may seem like the budget-friendly, eco-smart thing to do. And it may be -- but not if you use twice as much electricity trying to dry your hair into submission because you’ve started out with the wrong cleansing and conditioning regimen.

Here’s what you should consider:

1. Shampoo and conditioner. The newest science on hair care shows that different hair types have distinctly different structures. Fine hair, for example, contains 50 percent less protein than thicker hair, and curly hair has a twisted growth pattern that creates a lot of friction between strands. Coloring or relaxing your hair weakens the strand’s protective layer, which can leave it rough and dull. Finally, long hair has been exposed to way more washes, styling products and sun damage than shorter hair, making it more vulnerable to split ends, frizz and breakage.

What this means is that, to get your healthiest and most beautiful hair, you’ll want to choose products that are created especially for your hair type. Unless you and your partner have the exact same hair type, you’ll each want to choose the hair care products that suit your own hair texture.

Eco-friendly tip: Consider a two-in-one shampoo and conditioner to cut back on hair care product clutter.

2. Hair Dryer. Ionic, ceramic, tourmaline -- with high-tech innovations, today’s dryers do a lot more than simply blow hot air. Not every technological option is best for all hair textures, however. For example, tourmaline dryers contain ground mineral crystals that can speed up drying time by 70 percent. That’s a terrific time-saver if you have thick hair. But if you hair is fine, the extra power is a disadvantage. “Your hair will dry so fast you won’t have time to style it,” says stylist Sonya Dove, co-owner of the Doves Studio in Santa Monica, Calif. What’s more, says Reeve McNamara of Atlanta’s Van Michael Salon, “if your boyfriend or husband is going to share your dryer and his hair is thinning, the intense heat might burn his scalp.”

Keep in mind that with dryers, like jeans, fit is everything. “The single most important consideration when you pick a dyer is how it feels in your hands,” says Dove. If your hands are small, you might be most comfortable with a dryer that’s light and compact, while he’ll have better control with a heftier model.

Eco-friendly tip: Save electricity and still create the style you want by letting your hair air-dry before you use your blow-dryer.

3. Brushes. For starters, there’s the ick factor with sharing brushes -- they can spread lice or ringworm of the scalp. Beyond hygienic considerations, having a brush that’s suited to your hair -- thick, thin, curly or straight -- will make styling easier. If you have fine or thin hair, a ceramic brush with a small, square barrel will let you get right up against your scalp to lift your roots for a volume boost. To get the bounce and bends of a salon blowout on thick, coarse hair, choose a large, round brush that has a combination of synthetic and boar’s hair bristles. The nylon bristles will grip your hair, while the natural ones impart shine. If you have curly hair, skip the brush and opt instead for a detangling comb with a double row of extra-long teeth.

Eco-friendly tip: Clean out dead hair and dust with a tail comb every few days, and your brush should last about five years.

There may still be a chill in the air, but there’s a clear forecast for spring hair: It’s coming undone. As relaxed silhouettes, bright colors and textured lightweight fabrics paraded down the New York fashion runways, hairstyles also unwound -- think the disheveled glamour of Kristen Stewart, Blake Lively and Sienna Miller. 

“This spring, you’re perfect in a cool pair of jeans, a simple shirt and a beautiful jacket,” says Jeanne Yang, who styles the likes of Keanu Reeves and Katie Holmes, with whom she also designs the fashion line Holmes & Yang. “Your hair should have the same vibe -- like you’re pulled together, but not trying too hard. Nobody wants to look like they’ve just sat in a salon for an hour.”

Hair is getting shorter, cut in long layers just below the collarbone or at the shoulders. Beverly Hills stylist Byron Williams, who tends to the tresses of Selena Gomez and Eva Mendes, has been chopping flowing hair to 2 inches below the collar bone for an “edgier, fresher” take on surfer-girl sexy. Still, says, Lori Morris, senior editor of American Salon magazine, “There’s no big haircut of the season. Curls are relaxed and wild, and ponytails are loose and messy, as if you’ve just played tennis for an hour.” Jamal Hamadi, a favorite stylist of Kirsten Dunst, says come spring he’ll start with a shoulder-length cut that has jagged ends for more natural texture. “You want to look like a messy child,” he says.

Want to get a jump on spring hair? Here’s how to achieve what will be the season’s big four hair trends: 

1. Loose Waves
For this surfer-girl look, start with day-old hair that has some texture and body to it. Dampen your wavy locks with a texturizing spray, then scrunch random pieces while you blow-dry with a diffuser. If your hair is straight, wrap 3-inch chunks around a large-barreled curling iron. Finish with a light-hold hair spray.

2. Messy Braids
The look: braids with attitude. Spritz hair with a texturing spray, then part to the side, letting loose strands fall around the face. Gather hair into a slightly-off-to-one-side ponytail. Braid loosely and secure with an elastic band. Cover the band by winding strands of hair around it. Fasten stray strands with a bobby pin.

3. Textured Ponytails
The ponytails that bobbed down the spring runways were a bit less sleek than usual. With the tails textured and a little bit wild, they were a fetching mix of control and chaos. To get this new hair trend, smooth your hair with a dab of gel, and then brush it into a high ponytail. To texturize the tail, flat-iron hair and then mist it with sea-salt spray. Pull clumps apart for that cool, unkempt, out-at-the-club-till-4 a.m. look.

4. Hot-rollered Hair
For sexy tousled waves, wind haphazard sections of your hair into hot rollers. Leave in for five minutes, then remove and fluff the curls with your hands. If the waves are too voluminous, lightly brush. Place a dab of shine cream onto your palms and work onto the surface of your hair, then mist with a light-hold spray. “I wore hot rollers in my hair as I drove to a wedding,” says Yang. “When I got there, I pulled them out and headed to the party. Everyone kept telling me my hair looked fabulous -- little did they know I’d just styled it in my car!”

It’s the secret to top hairstyles like Beyonce’s barrel waves, Kim Kardashian’s sexy bedhead look and the glamorous cascade of curls that stars regularly show off on the red carpet. We’re talking about curling irons. “You can change the whole texture and personality of your hair in just a few minutes with a curling iron,” says Mezei Jefferson, a Chicago-based salon educator. “It will also help boost volume and add fullness to baby-fine hair.”

There are a variety of different curling irons that create curls of different size and tightness. Here’s how to find the one that’s right for you.

Spiral Curls
These curling irons have raised ridges on the barrel. To create the telephone-cord curls of Mariah Carey or Sarah Jessica Parker, simply twist your hair around the spiral pattern. The closer the grooves, the tighter the curls. For cascading ribbon curls with volume at the roots, choose a spiral iron with a tapered barrel.

Tips:

• Work with diagonal sections of hair to get closer to your scalp and create small bouncy curls.
• After you curl a section of your hair, pin it to your scalp to keep your curls intact as you continue styling the rest of your hair.

Loose Curls
Megan Fox and “Glee” stars Jayma Mays and Dianna Argon all rocked retro Hollywood glamour at this year’s Golden Globes with romantic, wavy texture. To create this look, choose a spring curling iron with a barrel size of at least 1 inch. The longer your hair, the larger the barrel you’ll want: Opt for a barrel of 1 1/4 to 1 1/2 inches for mid-length hair, or 2 inches if your hair is shoulder-length or longer. Spring curling irons are a great tool for novice curlers; the clip helps you keep a firm grip on your hair as you work.

Tips:

• Begin working from the middle of the hair shaft. Roll hair in the direction of your scalp. Then open the clip and feed in your ends.
• To protect hair, use as little heat as needed. Start with a temperature of 300 F. If that doesn’t give you the hold you want, gradually move on to hotter settings, increasing heat by 25 F at a time.

Waves

Double- or triple-barreled curling irons give you that just-back-from-the-beach look you’re craving in the middle of winter. This is the tool to choose if you want the tousled tresses of celebrity hair trends seen on Taylor Swift or Blake Lively.

Tips:

• For an authentic beachy look, start with day-old hair rather than just-shampooed locks.
• Apply a light holding spray before curling, and then work with horizontal sections of hair, rolling up to about 1 inch from your scalp.

Tips for All Types of Curls

• Apply a silicone-based serum before using the curling iron to protect your hair against heat damage.
• After curling, apply pomade or a silicone-based styling product. Work through your hair gently, and then finger-comb your hair to separate curls.
• Keep the barrel of your iron clean. Run a smooth, dry cloth over it when it’s still warm -- not hot -- to remove dust and product buildup.
• Make sure your hair is absolutely dry before you use your curling iron. Otherwise, you’ll end up with damaged hair and limp, ill-formed curls that will wilt in one to two hours.
• Always work with small sections of hair and hold the curl around the curling iron for 10 seconds, then release.
• Spray each section with a light mist of flexible-hold hairspray.

Photo Credit: @iStockphoto.com/coloroftime

With all the great products on the market, it’s easy to amass quite a beauty stash. When they’re kept too long, however, cosmetics can go from enhancing your clear complexion to compromising it with funky colors and smells -- plus they can spread bacteria.

“Over time, preservatives stop working efficiently and it’s possible for staph, fungus and yeast to contaminate makeup that’s been stored past its prime,” says New York City-based dermatologist Francesca Fusco. So resolve to keep your get-glam arsenal well-edited and up-to-date this year.

First thing’s first. These are the key items to have in your makeup bag, says Global Creative Design Director Pat McGrath of Procter & Gamble: foundation, concealer, powder, bronzer or blush, eye shadow, eyeliner, “bold” and “safety” lip colors, and mascara. Now use this cheat sheet to figure out when to toss different beauty products. Begin the countdown when you first open the product.

Foundation: Six Months to 18 Months
If you live in a hot, humid climate, liquid or cream foundation can break down in as little as six months. “Pitch foundation if there is separation or if the liquid starts to get grainy or extra-thick,” says celebrity makeup artist Sue Devitt. Stored in a cool place (not under the lights of your medicine cabinet), liquid foundation can stay fresh for as long as a year.

Powder-formula foundations will last an additional six months, as long as you wash the sponge applicator weekly.

Tip: Sniff your foundation when you buy it. “If the smell changes at all, toss it,” advises celebrity makeup artist Joanna Schlip, who has worked with Sandra Bullock and Sarah Jessica Parker. “It’s not worth holding on to the product and risking a breakout.”

Concealer: Six Months to One Year
Powder and stick concealers last a year, but liquid formulas should be replaced in half that time. Again, watch for shifts in color, consistency or scent.

Pressed Face Powder: Up to Two Years
Moisture or oil from your face can transfer back to the compact as you perfect your complexion, so prolong the life of face powder by cleaning your brush weekly with shampoo or a mild detergent, or replacing sponge or puff applicators when they become soiled from use. While pressed powders can last as long as two years, they should be discarded if a hard film forms on the surface of the powder before then, says Schlip.

Blush/Bronzer: Six Months to Two Years
A powder bronzer or blush will impart pure, true color for up to two years. Consider liquid blush or bronzer to be expired after 12 months. Cream blushes or bronzer often come in a pot or compact that you swipe with your fingers, so be alert to texture changes as soon as six months and discard after a year.

Powder Eye Shadow: Up to Two Years
Like face powder, these can be kept through two birthdays. Just be sure to practice clean-tool maintenance, says Fusco, so you don’t pick up bacteria from the moist eye area and transfer it back to the shadow pot or compact.

Liquid Eyeliner: Three Months to One Year
If your liner is drying out and you can no longer achieve a flirty Bardot cat-eye, you may need to say farewell at the three-month mark. However, liner can safely be used for a full year. “You’ll know it’s still good if it applies smoothly,” Schlip says.

Eye Pencils: One to Two Years
Luckily, your cache of colorful pencils can stick around a while. Most have a wax base, and bacteria can’t grow on wax, notes Devitt. Tip: Sharpen once a week to keep pencils fresh.

Mascara: Three to Six Months
As soon as the smell is off or the wand is nearly dry when you pull it out, it’s time for the heave-ho. “Mascara is the most likely culprit for breeding bacteria,” says Fusco, “because it’s stroked so close to the mucus membrane under the base of the lashes.”

Lipstick: Up to Two Years
Those bold reds and deep berries you save for glamour nights will safely last through a couple of New Year’s Eves or Valentine’s Days, since lipsticks generally contain wax in their base.

Lip Gloss: One Year
Although, with frequent reapplication, you’ll likely go through your favorite shades way before then!

Here’s a no-brainer: If you could tweak your beauty regimen to clear the clutter out of your bathroom cabinets, spend less time getting ready in the morning, and trim some dollars from your budget -- all the while helping the environment -- would you be willing to give it a go?

Well, all that’s possible by following a concept we’ve become very familiar with: multitasking. Choosing products that perform double -- or triple -- duty is a way to make your beauty regimen more eco-conscious, says Jenny Rushmore, global sustainability leader for Procter & Gamble’s beauty and grooming division. The three R’s of sustainability -- reduce, reuse, recycle -- is a catchy reminder of what our priorities should be when it comes to cutting back on waste. “What this means is that recycling is what you do after you’ve already reduced and reused,” says Rushmore. “It’s better not to buy bottled water than to recycle the water bottle, and that same idea applies to beauty products. Reducing the number of products you buy is the best place to start a more eco-friendly beauty regimen.”

Here are seven hardworking beauty products you can easily find on your drugstore shelves.

1. Shampoo-conditioners
These two-in-one formulas will help speed up your showers -- saving an average of 5 gallons of water for every minute you cut from your shower time -- and cut down on packaging. Best of all: Now you can find these double-duty wonders in formulas customized to add volume to fine hair, smooth frizz-prone locks or manage curls.

2. Razors With Built-in Shave Gel
All you’ll need to add is water to get your legs silky smooth. As convenient as that is at home, it’s especially helpful when it comes to getting a close shave when you’re traveling. No need to pack the shave cream: Simply toss a razor with a shave gel bar in your toiletry case.

3. Self-tanning Moisturizing Lotions
Add a glow to your skin as you soften and hydrate it -- without the orange streaks that conventional self-tanners can sometimes leave. To maximize multitasking, choose a facial or body formula with SPF 15.

4. Makeup Foundation With Benefits
Slash your beauty budget and your get-beautiful prep time with a foundation that also treats your skin with anti-acne or anti-aging ingredients, such as youth-restoring antioxidants, peptides, retinols and breakout-busters like salicylic acid.

5. Moisturizing Body Washes
Try these lathering marvels and you can step right out of the shower and into your clothes without having to pause to slather on a hydrating lotion. (Okay, a few seconds spent patting yourself dry with a towel is advisable.) Some advanced products also contain anti-aging ingredients that make fine lines less visible by improving skin’s elasticity, tone and texture.

6. Facial and Body Moisturizers With Sunscreen
With broad-spectrum SPF 15 or 30, these lotions provide the daily sun-shielding protection that dermatologists recommend. You can find formulas that are fast-absorbing and have a lightweight texture, so you’ll never be tempted to skip the sunscreen again. In fact, some facial UV moisturizers are so silky they provide the perfect canvas for your foundation, allowing you to skip the primer. Another step saved!

7. Baby Wipes
If these aren’t in your beauty arsenal, they should be. Unscented, hypoallergenic wipes are a gentle, portable and low-priced makeup remover that will baby your sensitive skin. Cold-weather tip: Stash a packet in your purse or toiletry case during cold and flu season so it’ll be within easy reach for on-the-go hand cleansing.