1) Use an antioxidant serum before your morning sunscreen. A good bargain is Vitamin C Lotion 30% by Revision (109$).
2) A light winter peel–lactic acid or salicylic acid–can rid you of dry, dull skin. Add a hyaluronic acid moisturizer to really smooth your skin. Good products: Hydrating Serum by Revision ($65) or HA5 by SkinMedica ($178 but worth it).
3) Continue daily sunscreen–SPF 30 or greater.
4)Don’t stop your nightly Retin A, but consider a lower strength for winter.