How to make your own BRO TANK! 1) Start with a plain T-shirt, or even better, a T-shirt with a sports logo on it. 2) Cut the arm holes out, first just cutting them at the arm-hole/shoulder seam on each side. Then cut as long as you would like to (vertically). 3) On the top layer of fabric in the front, cut a U-shape into the ribbed collar, making the bro-tank straps about two inches wide. You should have a T-back tank. 4) Flex, with or without the tank on.