Rachel BilsonTHE LOOK Low ponytail HOW-TO "Start with hair powder on dry hair," says stylist Wendy Bond. Add a little messy texture by blow-drying hair. Gather hair into a low ponytail at the base of the neck and allow face-framing layers to fall out. Finish with a light coating of hairspray. INSIDER TRICK By starting with hair powder, you enhance the texture of the hair. BUY ONLINE NOW Hair powder, Bumble & Bumble, $41; fredsegalbeauty.com.