Okay, I'm creatively challenged, too! You can find tons on the DISign boards. Kara gave me the link,
http://s205.photobucket.com/albums/bb317/rumblytumbly_bucket/, (thanks, Kara!) and then I opened the
designs I wanted, copied and pasted them to My Pictures. My DDIL is going to do the rest - I don't know how to change the writing, but apparently, you send the design to Microsoft Paint, then remove the name that is there and write the names you want in there. You can download Walt Disney script. I can send you the file, if you want.
Here's another suggestion: You can join a thread of a DISigner you like and ask them for the names, and viola! It appears on the thread for you to copy and paste.
The transfer paper can be purchased at Staples or at the fabric store. You can just use undershirts, or plain T-shirts, whatever. I have read that you don't iron it on your ironing board - not hard enough. Use a cutting board with a pillow case over it and NO STEAM!
I'm going to use a t-shirt with a little thicker material that includes spandex or lycra. I just like wearing that fabric better. My DDIL wants one of those thin ones that the kids like these days.
You should try to make the shirts - it would be fun! If you get them done, post some pics!