How can i make my own shirts/ posters?

Have you ever heard of t-shirt transfers? They are pretty cheap, basically it is a sheet of paper, you print anything you want on it, peel it off, iron it on to a plain shirt and there you go! a customized shirt. In the UK. If you guys have Staples,office depot, micheals craft store over there. Then go there and ask for t-shirt transfers or call.