THE BARELY DONE BRAID
There's nothing kidlike about this look--except how unbelievably easy it is to create. In fact, you can do it on wet hair without a drop of product (unless you have fine hair, in which case a dollop of mousse will give it some hold). While your hair is damp, finger-comb it back off your face and, starting at the crown, make a tight braid, shifting it to one side as you go. Wrap an elastic around the end, then gently tug a few spots along the sides of the braid and your hairline to loosen some pieces. "The softer and more imperfect the style is, the sexier and more grown-up it looks," says Tresemmé celebrity hairstylist John D., who has worked with Jennifer Garner. (If you're good at this stuff, start out by making a small French braid on one side of the front of your hair, as pictured here. Then tuck the end into the main braid.) When the sun goes down, unravel your hair and--ta da!--instant waves.
THE EFFORTLESS TWIST
Hair gone crazy in the heat? "A bun is the quickest way to look instantly polished," says celebrity hairstylist Tim Rogers, creative director of Living Proof hair care, who has worked with Kate Hudson. But a slick bun can look harsh. To make it soft, use your fingers instead of a brush to gather your hair at the back of your head. Wind it into a chignon (if you have long, heavy hair, secure it in a ponytail first), then use U-shaped hairpins--not bobby pins, which don't hold as well--to pin it down at the top, bottom, and each side of the twist (try Sta-Rite Hair Pins, $2.29). Don't sweat any fuzzies around your hairline. "They add to the romantic feeling of the look," Rogers says. Bonus move: When headed to the pool or beach, saturate your hair with a deep treatment like Biolage Fortethérapie Intensive Strengthening Masque, $16, then twist it up. "The mask acts as a barrier, protecting your hair from chlorine and salt water," says Rogers. "Plus, the sun's heat helps the nourishing ingredients penetrate, so when you rinse it out, your hair will be incredibly shiny."
THE LOW, SEXY PONY
If you have fine hair, you know that humidity can actually be a blessing--especially when it comes to stepping up a basic ponytail. "The moisture in the air swells the hair cuticles, giving the tail a fluffy, stylish finish," Rogers says. For the prettiest effect, place the ponytail just above the nape of your neck, about level with your jawbone. "This really elongates your neck," he says. To keep the front of the style smooth, mist your fingers with a humidity-fighting hairspray such as Tresemmé Climate Control Finishing Spray, $4.49, and pat down any flyaways at your hairline and on top of your head. An elegant touch: Wrap a small section of hair from the ponytail around the base to hide the elastic, then pin the ends in place discreetly underneath. Swoosh!