The Secret to Olivia Wilde's Sleek Summer Waves Costs Just $4

Beach waves are the ultimate Summer hairstyle, but windblown and frizzy are two very separate looks. InStyle spoke with Olivia Wilde's hairstylist to get the must-have product for sleek waves this season. While bad hair days usually feel like an inevitable part of summer, that certainly wasn't the case for Olivia Wilde at the premiere of her new movie, Third Person, in New York City. The steamy weather didn't stop the star from stepping out in sleek waves - in fact, there wasn't a hint of frizz ...