Stylist to the stars Rachel Zoe knows that clothes and accessories aren't the only elements that make an overall look "bananas!"—you must also consider what's underneath. Finding the perfect undergarments is the inspiration behind "The Zoe Report Presents—Behind Clothed Doors: 20 Hidden Essentials," a new guide filled with the uber-stylist's must-haves, launching on RachelZoe.com this coming Monday. "This guide aims to help my Zoe Report readers make any outfit even more fabulous by helping them find the perfect hidden base for any and every occasion," Zoe told us. "Never neglect your undergarments—what you wear underneath the perfect outfit is just as important as the outfit itself." We've got an exclusive sneak peek at some of the featured items—click on to find out what Zoe loves about each!