After Halloween I purchased 3 t-shirts for 70% off the origional price which made for a great deal for me. The problem was that they all shrunk in the wash to sizes I can't imagine many people could have fit into. One of them I couldn't even begin to fit over my head. Luckily there are methods of stretching one's t-shirt to a better fit.
Start by cutting the collar away from the back of the t-shirt.
Cut the collar away from the front as far down as you want to go without actually removing the collar.
Clean up the collar then lay your shirt so the top side seams meet.
Cut out a pie wedge shape so that your shirt becomes off-the shoulder.
Stretch the shirt so it curls and you're done!