Preservation starts with prevention
Keeping your suede in top condition begins with proper everyday storage and care. Start by treating your garment with a suede protection spray prior to wearing for the first time. A light coating of protectant goes a long way to protecting your garment from small amounts of moisture and stains. Be sure to test your suede protectant on the underside of your garment before apply however, as some sprays will darken/discolor your garment on contact.
The second stage of protection is proper storage. When not wearing them, be sure to keep your suede garments in a dark, dry, cool place with adequate airflow and low humidity. Light and moisture are major enemies of suede; the former fades your material, while buildup of the latter will quickly degrade it. In addition, be sure not to store your suede garment in plastic, as the lack of airflow plastic creates will trap moisture inside with you garment, and promote growth of mildew on it's surface.