January 2007

I. Cut Layers into Long Hair

To put it, well, bluntly, a long, blunt cut looks dense and shapeless, while "layers give hair sexy movement," says N.Y.C. hairstylist John Barrett. "Layers strengthen bone structure," adds N.Y.C. stylist Eva Scrivo. For the most flattering results, pros recommend cutting layers into your hair from lip level down. "Do minimal layers to frame the face and stronger ones throughout," advises stylist Chris McMillan, who creates Jennifer Aniston's sexy shag. "Layers allow Jennifer to keep her hair long without it becoming too heavy, and they give her the option to wear her hair naturally wavy or straight."

02 of 10

II. Use Heat to Create Shape

Hot water, blow-dryers and hot tools soften the structure of hair and make it more receptive to curling or straightening. "Heat breaks down the hydrogen bonds in hair so you can reset it in the shape you want," says Pantene senior scientist Lesley Bride. Beware: Excessive heat damages strands, so use tools with adjustable thermostats. "Use higher heat for thick, curly hair and lower heat for fine or colored hair," Barrett says. And since it takes time for strands to set in a new shape, "try not to disrupt the style while hair is cooling off," says Bride.

03 of 10

III. Always Make Updos Look Effortless

In other words, scrap any complicated or tendril-happy style befitting a bridesmaid, prom queen or ice-skater. "Keep updos simple and pretty," says stylist Byron Williams, who created Mischa Barton's soft, spontaneous-looking chignon. First he curled random sections of her hair with an iron, then he twisted and pinned pieces to one side, securing them with bobby pins and setting the style with light hairspray. To get a similar look on your own, tease hair at the crown of your head to create a bit of volume, twist hair into a low bun and pin it into place. For a stylish accent add a skinny black headband or two.

04 of 10

IV. Mix Up Your Shampoo Routine

Much like your skin and body, hair needs different kinds of nourishment at different times, so rotate shampoos accordingly. It's easy: If your hair looks and feels normal to dry, wash it with a creamy, hydrating shampoo (such as L'Oreal's, right). On days that tresses feel oily and weighed down with product, reach for a clarifying shampoo (like Klorane's, center). Because deep-cleansing shampoos have a high detergent content that strips the natural oils from hair, experts recommend using them only once or twice a week.

05 of 10

V. Make your Blowout Last More Than a Day

Top pros say a good blowout should look full and shiny for up to three days, even after sleeping and exercising. At bedtime, Robert Vetica, who works with Salma Hayek (above), suggests piling hair on top of your head in a loose bun or putting it in a loose braid (you'll have soft waves the next day). In the morning, says stylist River Lloyd, "spritz Evian water on areas that need to be fixed, and blow-dry." Pre-workout, secure hair into a loose ponytail and place a terrycloth headband along the hairline, Vetica says. Afterward, sprinkle dry shampoo near roots to absorb perspiration and smooth hair with a wide-tooth comb (not a brush, which spreads oil down the hair shaft).

06 of 10

VI. Blast Hair with Cold Air to Create Shine

"When cold air or water hits hair, the cuticles contract," says Scrivo. As a result the cuticles (scales on the surface of the hair) lie down flat and tight and reflect more light, and hair looks glossy. How do you make this happen? For your final rinse in the shower, make the water as cold as you can stand. And when you're almost done blow-drying a section of hair, says L.A. pro Jonathan Antin, press the cold-shot button for five seconds.

07 of 10

VII. Don't Touch Curly Hair After Applying Products

Heat and moisture from your palms will create frizz on natural curls and waves, so take a hands-off approach. Apply styling products to wet hair and let it air-dry. "When it's totally dry, use styling cream to tame it," says pro Louis Licari. Rub the cream between your palms and gently push the waves toward the scalp. Hold loosely for five seconds and let go.

08 of 10

VI. Choose Sideswept Bangs Over Short, Blunt Ones

"You can never go wrong with a long, wispy, sideswept bang," says Kim Kimble, who created Beyonce's sexy fringe. "It works on any face shape." To style a swooping bang, Kimble recommends spritzing with light hairspray and curling bangs with a large iron while angling the iron toward the desired side. "Be sure to fit all of your bangs on the barrel at once, and don't curl them too tightly," she says.

09 of 10

IX. Embrace Hairspray

Shellacked hair is so old-fashioned. Luckily today's sprays contain little alcohol, spray in a fine mist, and create texture and soft hold. "Keep the bottle far away so particles can disperse in the air," suggests Lloyd. After spritzing, "run your hands through hair and shake it so it won't dry hard," says Eva Scrivo.

10 of 10

X. Tweak Your Hair Color Seasonally

Color experts recommend lightening up for spring and summer, when complexions tend to be warmer and more golden, and going darker for fall and winter, when skin is paler. Colorist Tracey Cunningham changes Jennifer Lopez's tone in several steps (not all at once) when the seasons change because it's less damaging. But not everyone has to go up or down multiple shades. "Sometimes less is more," Cunningham says. "Weaving darker colors through the hair adds richness and isn't too extreme for winter, and for springtime highlights are great."