All you have to do is download the transfer, print it on iron-on transfer paper (you can get it at Walmart, Target, Staples, anywhere you can get printer paper, really) and follow the transfer paper directions. The transfer itself is a large, hi-res 8.5" X 11" PDF document image in reverse so that it'll appear correctly on your t-shirt once you iron it on. Enjoy, and remember that Jeebus said share, so link to this and pass them on. Doing it at home will save time and money instead of paying CafePress to do it for you. This way you can keep the costs down because for the price of one CafePress shirt, you can buy several blank tees and a pack of transfer paper and have lots more than one.
To save each .PDF design, click on the [DOWNLOAD DESIGN] link and open the file. Go into the File menu at the top and save the document or at least a copy of it. Feel free to link to this post, and thanks in advance for it!