During the Winter my Main Three Points of Proper Skin Care are:
1. Moisturize, Moisturize, Moisturize! Winter can really dry out your skin. My personal favorite moisturizer right now is Dermaquest's Advanced B-5 Serum for Dry skin or Dermaquest's Rejuvaderm for Oily to Problematic skin.
2. Make sure to exfoliate at least twice a week, so that your moisturizer can penetrate into your skin. My favorite exfoliator by far is the Japanese Wash Cloth.
And last, but not least:
3. Remeber to wear your sunscreen. You can still get sun damage even when the sky is gray. Cloud cover can even intensify the affects of the sun if you are outside too long. So be sure to apply a light SPF each day.