Beauty 101: Healthy hair

You know not to lather, rinse, repeat. You know not to shampoo every day. But unless you're a professional hairstylist, you're probably still washing your hair the wrong way.

1. Look at how much shampoo you're using. Now cut that in half. You should use a quarter-size amount. "Shampoo removes all of the dirt and oil from your hair, then it starts stripping away essential oils and lipids that prevent dryness and breakage," says Hawkins. Shampoos labeled moisturizing, curl-enhancing, or color-protecting are relatively kind.

2. Do not vigorously massage your shampoo. That roughs up the cuticle, causing frizz, flyaways, and miniscule tangles. Rub your shampoo between your hands, gently massage the roots with your fingertips, and smooth what's left on your palms over the length.

3. Rinse (duh), but don't condition just yet. Give your hair a few gentle squeezes first, since "excess water dilutes your conditioner and prevents hair from soaking up moisturizing ingredients," says Hawkins.

4. Now condition. Use a moisturizing or color-protecting formula (ones with argan, avocado, or grape-seed oil are especially hydrating). "Apply it generously in long, fluid motions," says Hawkins. Wait two minutes before rinsing. It takes that long for conditioner to adhere to the hair.

5. Water, and the chlorine and minerals in it, fade color. And hot water fades color faster. Get a filter for your showerhead or turn the temperature down when rinsing your hair, and your color will look fresh longer.

The basics: Coat your hair with deep conditioner from the midshaft down. Make sure you apply it in the shower so all the conditioning ingredients can sink in. If your hair is really adamaged (you know who you are), leave the mask on after your shower. Wrap your hair in a towel for ten minutes, then rinse.

If you have fine hair: Skip thick masks with oils or silicone. Instead, use a deep conditioner with volume-boosting protein, like Nioxin Intensive Therapy Deep Repair Hair Masque or Dove Damage Therapy Conditioner (nioxin.com; Dove, target.com).

If you medium to thick hair: Look for products with essential oils, like avocado, argan, coconut, or sunflower, or keratin. Try L'Oreal Professional Mythic Oil Nourishing Masque or John Frieda Full Repair Hydrate and Rescue Deep Conditioner (lpsalons.com; John Frieda, drugstore.com).

If you have coarse hair: In the morning, use a dollop of a pure oil, like Josie Maran Argan Oil, to soften the ends and top layer, says Potempa. Once a week, use a dense mask with a rich emollient such as shea butter. Try Clear Scalp and Hair Beauty Therapy Ultra Shea Deep Nourishing Mask (Josie Maran, sephora.com; Clear Scalp and Hair Beauty Therapy, target.com).

If you have color-treated hair: "If you color your hair, you should be using keratin treatments to strengthen it," says Fusco. Add a dropperful of protein-rich KeratinEarth Versaplex Infusion to your deep conditioner. "If your hair is really brittle, hot-oil treatments like VO5's will weight down flyaways better than a mask," adds Hawkins (keratinearth.com; vo5haircare.com).

1. Breakage. The pros agree the best thing you can do to prevent future damage is use a heat protectant when blow-drying. Coax any flyaways down with two shots of lightweight hair spray. "First aim it at the hair in the direction you want it to lie," says Hawkins. "Then spritz it on a paddle brush and use that to smooth the hair down."

2. Flakes. Quick quiz: Do you only see flakes in the winter? You've got a dry scalp. Use a moisturizing shampoo, and put conditioner right on your scalp for five minutes each week. Do you use styling products like volumizer on your roots every day? Scrub away the residue weekly with a tablespoon or sugar or clarifying shampoo. Do you have flakes and no clue why? Use an anti-dandruff shampoo, like Head and Shoulders Damage Rescue, twice a week (walmart.com).

3. Split ends. Stop putting off your next cut—every eight to ten weeks is the rule, says Blandi. And again, if you own a blow-dryer, you must own a heat-protectant spray. Heat causes and exacerbates split ends. Tresemme Split Remedy and Nexxus Salon Hair Care ProMend conditioners and serums temporarily glue split end together (tresemme.com; nexxus.com).

4. Zero shine. This one is surprising: "The most common cause is shampoo residue," says Fusco, who recommends rinsing out your shampoo for a minute longer than you normally would. Then boost your shine with an at-home glaze, like Oscar Blandi At Home Salon Glaze Shine Rinse (oscarblandi.com).

What to always—and never, ever—do to keep hair in top shape.

Always: Use heat-protectant spray. It prevents frizz, flyaways, split ends, breakage, and dullness, says hairstylist Oscar Blandi of the Oscar Blandi Salon in New York City. Try L'Oreal Paris Color Vibrancy Dual Protect Spray, wchich contains light reflectors to add shine (drugstore.com).

Always: Choose tools wisely. Detangle with a wide-tooth rubber comb (like one by Beuy Pro) and style with a boar-bristle brush. Pick an ionic blow-dryer with 2,000 watts, a ceramic iron, or keratin-infused tools, like those from Remington Keratin Therapy (Beuy Pro, btypros.com; remingtonproducts.com).

Always: Take the nozzle off your blow-dryer. Point it down, says hairstylist Sarah Potempa. "The heat will be more diffused."