You're so vain, and that's okay with you. Now is a great time to start an age-defying beauty regimen. Experiment with retinoids (vitamin a derivatives). Not only do these compounds help exfoliate the skin from within, they're hydrating (excellent for dry cold-weather skin). Ask your doctor about renova, avage and differin. For less potency, experiment with over-the-counter brands. And guys, retinoids are excellent at preventing ingrown hair.