"I straighten my hair with a flat iron up to three times a week. Will I destroy my hair by doing this?"

--Hannah, 17, Calabasas, CA

Although straightening your hair with a flat iron isn’t the best way to maintain a healthy mane, you’re doing the right thing by minimizing how often you use it. Repeated exposure to high levels of heat from styling tools can begin to weaken hair, leaving it prone to breakage and split ends. One way to prevent serious damage is to use a ceramic flat iron – it distributes heat more evenly than other irons to avoid frying spots. Before you style, spray your hair with a thermal protecting lotion, which will work with the heat of your iron to lock in moisture. Try CHI 44 Iron Guard Thermal Protection Spray, $13, available at Target.com. It also has lasting style memory, so you can skip a day of washing to give overheated locks a rest. Finally, apply a repairing serum – like Göt2b Hottie Oil Therapy Repair Blasts, $6 for three, at Target and Walgreens stores – in the shower once a week to strengthen strands and undo any damage.

Meredith Gray, Assistant Beauty Editor - Seventeen Magazine