Celebrity hairstylist Ursula Stephen says the key to straight hair in the summer is a ceramic wet-to-dry flat iron. First, "apply a protecting spray, such as Motions Heat Seeker Protecting Spray ($23; amazon.com
) to damp hair and then use the iron," she says. The iron helps lock in moisture and fight flyaways. Bonus tip: "After using the iron, apply the spray again on dry hair to help protect against the sun's UV rays."