There are a number of t-shirt specific resources that can help you promote your cafepress store for little to NO cost. One such resource is T-ShirtCountdown.com.
T-ShirtCountdown.com allows visitors to shop, vote for, and view your t-shirt designs from one convenient site. You can add one listing to t-shirtcountdown for free and have your t-shirt image linked to your store from our site. Just fill out the form on this page. (Rodney)