Photo: JGI/Jamie Grill/Getty Images

2 of 6
You're skipping serum.
While you may be well aware of the dangers of the sun's UV rays, there's another outside assailant to take note of: pollutants, says Joyce Imahiyerobo-Ip, MD, a board-certified dermatologist who is director of cosmetic dermatology at South Shore Medical Center in the greater Boston area. "Our environment is getting increasingly more polluted. Skin is being exposed to free radicals, which research shows causes premature aging," she says. Use an antioxidant serum in the morning before applying moisturizer. Look for formulas with vitamins C, E, ferulic acid, green tea or lycopene, all effective antioxidants.