Insufficient sleep and stress are biggies when it comes to acne and premature aging. "That old adage—get your beauty sleep—is real," says Wechsler. During sleep, your body produces human growth hormone (HGH, aka the antiaging hormone), which rebuilds and rejuvenates skin cells. But when you're anxious and losing z's, levels of the stress hormone cortisol skyrocket, disturbing the hormonal balance needed for a healthy complexion. Excess cortisol can also attack collagen—a protein that helps keep skin taut and wrinkle-free—causing inflammation-related issues, from joint pain to acne, says Shawn M. Talbott, PhD, author of Cortisol Control and the Beauty Connection (Hunter House, 2007).

Beauty fix: It only takes nine days (including two weekends) to get back on track, says Wechsler. Aim for eight hours of quality sleep nightly. Not feasible? Add an extra half-hour per week or take 20-minute naps. Other skin-saving habits: Exercise regularly to improve circulation and to release endorphins, stress-fighting neurotransmitters; and make time for friends. "Actual face time with friends has been shown to decrease cortisol levels," says Wechsler.