Autographed programs and ticket stubs have their greatest value if some historical moment occurred at the event, or if it is an event considered important (like a World Series or Super Bowl). Who signed the item enhances its value as well. To preserve the value keep these items in protective sleeves.
Autographed photos can be very desirable especially if it is considered scare. The most common sign is 8×10. For resale if it is personalized it will diminish its value. Also having authentication from a reliable source will help for resale purpose.
Autographed postcards can be fun to collect. The best way is to send a stamped self-addressed one to an athlete, and ask that he or she sign it on the cover and send it back by return mail. For added value, ask them to include a brief inscription on the back of the postcard.
Lithographs, posters, and prints have a curious value fluctuation. Limited edition and numbered prints that are autographed are of greater value, than those that are signed and have been mass produced. For the greatest return, frame the items and protect them from sunlight.
Index cards are a great way to collect autographs. Because of their small size, they are easily transported and stored. You can also restrict autographs to a single player to help enhance the value of the card. Try to find cards that are not made of acid-based paper to prevent deterioration and yellowing.
Autographed helmets, especially those carrying a team logo, are of great interest to collectors. If the helmet has game experience, the interest is even greater. Do not try to repaint or repair the helmet if it is damaged – these only add to its value.