Here's a quick project that should be fun for you to try. It could also make the starting point for a design lesson in school.
The paper T-shirt file at the end of this post comes with a blank shirt for your own design as well as two pre-designed shirts. Download the file. Print out the parts onto ordinary photocopier/printer paper. (No need for card with this project) Just print out page one if you are creating your own design. The assembly should be fairly self explanatory, I'll try and get some step by step pictures up tomorrow or Sunday. I hope you enjoy the project! I'm off for an early night – struck down, as I am, with a stomach bug. Bleugh.