I cut the tee shirts apart and the shoulders and the sides. Then I fuse a stabilizer on the back of them, about a half yard for each one. I lay the tee shirts face down on a teflon pressing sheet and fuse the interfacing to the back. Then and only then, cut the tee shirts the size you want them to be. They don't all have to be the same size. You can add strips of fabric on the smaller ones to make them larger. Use your imagination and sew them together. You can add appliques and embroidery and pieced blocks if you want to. You are the designer. Tee shirt quilts are fun to make.