Dermatologists, beauty editors, and celebrities alike swear by the Clarisonic cleansing brush ($199). We had a chance to talk to Clarisonic cofounder Dr. Robb Akridge and discovered something unsettling — we've been missing some crucial steps in our daily Clarisonic skin-care routine. Sure, we know how to clean it, but these tips will help you get the most out of your favorite skin-care device.