From left: Louis Vuitton’s nylon and Lycra dress, louisvuitton.com. Mokuba ribbon. Louis Vuitton’s nylon and Lycra dress, louisvuitton.com; Nina Ricci’s stretch cotton lace bodysuit, at select Nordstrom stores, 888.282.6060; Jeffrey, New York, jeffreynewyork.com; Adresse, Philadelphia, adressephiladelphia.com. Mokuba ribbon. From left: Miu Miu’s silk tulle dress with crystal embroidery, at select Miu Miu stores, miumiu.com....

