You should be washing your face twice daily at minimum, but the time of day that's undoubtedly most important is at night. Your skin has just gone through a day's worth of sweating and collecting dirt and grime from the environment, not to mention makeup has been sitting on the skin's surface and inside each pore. "That extra oil with sunscreen and makeup will cause some major clogging," warns Ulla Gaudin, makeup artist and hairstylist. She recommends using a gentle cleanser formulated for everyday use, such as Philosophy's Purity Made Simple One Step Facial Cleanser, $24.