Step 3: Cut out the T-Shirt shape.
Now that you have your giant peice of duct tape. Cut out a T-shirt shape. I would find a very well fitting T-Shirt and trace around it with a NON-Permanent marker. Then Cut it out. Do this for both peices.
Also it might be a good idea to make them WAY bigger then your shirt because this could turn into a duct tape straight coat if you do this wrong.