The easy, step-by-step guide to making the best of—or transforming entirely—the hair texture you were born with, whether straight or curly.

Photo: Mary Rozzi

To Make the Most of Straight Hair

Your best cut: If your hair is on the thick side, go   long. The weight will help prevent puffiness. And to give it movement,   add in a few                                      graduated layers, à la Gwyneth   Paltrow or Sofia Vergara. If it’s finer, opt for a choppy shag or a   blunt bob. Both can create                                      the illusion of fullness, says New   York City salon owner Paul Labrecque.

How to style it: Use a deep-cleaning shampoo. Scalp oils easily migrate down straight   hair and can make it feel greasy. Follow with a lightweight                                      conditioner on the ends only. Don’t   load up on styling products, which can flatten. Instead, blow-dry with a   smoothing paddle                                      brush, aiming the air toward the   ends. (Blow-dry directly into your hair and you’re apt to create frizz.)  

And the real secret                                      to lustrous, shampoo-commercial   hair? “Light reflection,” says Ken Paves, a celebrity stylist with   salons in Los Angeles and                                      Clinton Township, Michigan. Rub   shine serum between your palms, then smooth onto hair.

Photo: Mary Rozzi

To Make Straight Hair Curly

Your best cut: If you plan to wear your naturally   straight hair curly more often than not, choose a midlength or longer   layered cut, says Renee Cohen, a stylist for Serge Normant at the John   Frieda salon in New York City. Layers add texture, creating the illusion   of “bend” (stylist-speak for waves), since they stack up on one   another.

How to style it: Use moisturizing   shampoo and conditioner. “Hydrated hair holds its style, while hair   that’s dry falls flat,” says F. Wayne, a stylist in New York City.  

Towel-dry hair and prep with mousse. Then blow-dry with a medium-size   round brush. Working in two-inch sections, lift hair from one side of   your head to the other as you dry, focusing the air on the roots. This   technique, called overdirecting, builds volume. Finish by winding   portions of hair around a medium-barrel curling iron, then setting the   curls with lightweight hair spray. (Skip the spray if your hair is   fine—the mist will just weigh it down.)

Photo: Mary Rozzi

To Make the Most of Curly Hair

Your best cut: All curly hair isn’t created equal. The most flattering crop depends on   whether you have loose waves or tight ringlets. Celebrity stylist Sarah   Potempa suggests seeing a stylist who specializes in cutting hair dry.   This way, she can more accurately see how your curls fall and snip   accordingly. But in general “curly hair should never be worn one length,   which can give you the dreaded pyramid effect,” says Labrecque. Also   verboten is razor cutting, which can slash already fray-prone curls and   leave them frizzier.

How to style it: Use   hydrating shampoo and conditioner. The outer cuticle layer of curly hair   tends to lift up; the extra moisture may help strengthen weak strands   and prevent breakage. Next, add a nickel-size drop of styling cream (more if your hair is thick) to towel-dried hair. Then shape your hair   into twists and dry it naturally or with a diffuser. If you want looser   curls, finish by winding sections of hair around a large-barrel curling iron. It may seem counterintuitive, but this can straighten coils a bit.

Photo: Mary Rozzi

To Make Curly Hair Straight

Your best cut: For ease of styling, Labrecque recommends going to extreme lengths. Very short curly hair can be blown straight in minutes flat. Very long curly hair tends to flatten under its own weight. Steer clear of midlength cuts unless you’re committed to daily blow-outs.

How to style it: Straightening curly hair is a little like ironing a shirt, says Jason Low, also of the John Frieda salon, in New York City and Los Angeles: “You need consistent tension, strong heat, and some moisture.” Start by using antifrizz (sometimes labeled “smoothing”) shampoo and conditioner. Next, work a pea-size drop of hydrating styling cream through damp hair, spritz on a heat-protectant spray, and crank the dryer up to its highest heat, which will help hair dry fast, before it has a chance to curl. Pull hair taut while blowing on a low speed and aim air toward the ends to avoid flyaways. Finish with a flat iron and a drop of shine serum.

Photo: Jens Mortensen

Products to Make the Most of Straight Hair

1. Tresemmé Deep Cleansing Shampoo (bottom) and Smooth and Silky Conditioner (top)

To buy: $4.50 each at drugstores.

2. John Frieda Frizz-Ease Sheer Solution

To buy: $10 at drugstores.

Photo: Jens Mortensen

Products to Make Straight Hair Curly

1. Dove Daily Moisture Shampoo (top) and Conditioner (bottom)

To buy: $4 each at drugstores.

2. Nexxus Pro-Mend Bodifying Mousse

To buy: $12, ulta.com.

Photo: Jens Mortensen

Products to Make the Most of Curly Hair

1. Garnier Fructis Triple Nutrition Fortifying Shampoo (top) and Cream Conditioner (bottom)

To buy: $4 each at drugstores.

2. Paul Labrecque Curly Style

To buy: $22, paullabrecque.com.

Photo: Jens Mortensen

Products to Make Curly Hair Straight

1. Suave Professionals Keratin Infusion Smoothing Shampoo (left) and Conditioner (right)

To buy: $3.50 each at drugstores.

2. Alterna Bamboo Smooth Anti-Breakage Thermal Protectant Spray

To buy: $24, sephora.com.

3. Keratin Complex Infusion Replenisher

To buy: $30, keratincomplex.com.