Stepping out in New York following the FIFA Club World Cup, Bieber wore a red lace slip dress from Christian Dior's Fall 2005 collection by John Galliano. Earlier this summer at Coachella, she wore a similar slip from Dior too. © Getty ImagesWhat makes the look so appealing is that it taps into exactly what we want from our summer wardrobes. © DebuteIf linen dresses have long been the uniform of summer, the lace slip is fast becoming their cooler, slightly more daring younger sister. Shop: Summer Mini Slip DressesRenee Washington, Grazia's digital fashion and beauty writer, lives online.