For the T-shirt design in my final assignment I used customink.com
The first step is to select the type of product you want to design.
The 2nd step is to add the text you want to add to the shirt, and decide the size and color of the text you wish to put on your shirt.
the last step is to add the graphics you wish to add to your shirt if you wish to add it.
the next step would be to order your shirt but in this case I skipped that step.