Who: Hailee Steinfeld The Expert: Marcus Francis, celebrity hair stylist The Look: A fresh, curled style that's perfect for summer parties! The Tip: On damp hair apply Leonor Greyl mousse to the scalp by raking it through the roots with your fingers. Add a bit more to the mid shaft and ends, followed with a few spritzes of Davine's Sea Salt Spray. Comb through to detangle and dry with a diffuser to bring out the hair's natural curl. To add a little more polish to the texture, use a 1"…