ELIZABETH OLSEN'S STYLE: A below-the-collarbone cut with soft, blended layers starting at the chin. WHAT MAKES IT COOL: Olsen's hairstylist Mark Townsend used thinning shears to create hidden layers throughout the bottom few inches of her hair. "Some long bobs can look drapey and drab," he says. "These layers add volume and thickness." WHO IT WORKS FOR: "I really believe this is a haircut that would work on almost everyone," Townsend says. (We agree! Learn more about the flattering long bob.) If your hair is curly, keep the layers long to weigh down too-bouncy spirals; if your face is long, have you stylist start layering at lip level. "That way, you'll downplay the length of your face a bit," Townsend says.