Oily Hair

Chances are, if you have oily skin, you have an oily scalp. You need a shampoo that gets rid of excess grease without stripping hair.
RS Pick: Aussie Dual Personality Root Cleanser + Tip Mender, $3.50. This gets rid of excess oil and balances moisture.
To Buy: At drugstores.

Normal or "Virgin" Hair

Hair that has never been chemically colored, straightened, or permed and has little or no damage is the easiest to shop for.
RS Pick: Citré Shine Fresh Fusion Revitalizing Shampoo for Normal Hair, $4. This gentle formula contains grapefruit and mandarin-orange extracts, which give hair shine.
To Buy: At drugstores.

Fine Hair

Wash with a volumizing or thickening formula, which has fewer conditioning agents that can weigh hair down, says Walker Allen, director of product development for Bumble and Bumble, in New York City.
RS Pick: Infusium 23 Maximum Body, $5. This shampoo strengthens thin and weak hair with panthenol, otherwise known as vitamin B5.
To Buy: At drugstores.

Thick Hair

Use a double portion of shampoo in a formula for your hair type — normal, oily, dry, or chemically treated.
RS Pick: Redken All Soft Shampoo, $9. This favorite of Suzanne Mason, a hairstylist with the Zano Salons, in Chicago, softens hair with avocado oil to make it more manageable.
To Buy: www.redken.com for salon locations.

Colored or Chemically Treated Hair

Use a protein-based shampoo (common ingredients include silk amino acids and extracts of wheat and soy) to help reinforce weak areas.
RS Pick: Joico K-Pak Reconstruct, $12. This contains a blend of amino acids that adhere to damaged areas on the hair.
To Buy: www.joico.com for salon locations.

Dry or Damaged Hair

You need a shampoo that will soften your porous (and, most likely, dull) hair and minimize static. Hydrating ingredients like glycerin and collagen help restore the moisture balance.
RS Pick: Dove Advanced Care Therapy Shampoo, $6. This inexpensive pick repairs roughness and dryness with silicone and has glycerin for deep hydration.
To Buy: At drugstores.

Wavy or Curly Hair

Textured hair tends to be dry, so use a formula with silicone or oils (such as almond) to avoid frizz.
RS Pick: Kérastase Bain Oléo-Relax, $24. This is the best smoothing shampoo, says Patrick O'Hara, owner of the Patrick O'Hara Salon, in Dallas. Silicone and palm oil lend shininess and a smooth feel.
To Buy: 877-748-8357 for salon locations.