Here's a way to turn your t-shirts into a cute two-tone drawstring backpack- or, since it's function-reversible, a drawstring pouch!
All you need is two t-shirts (and cutting/sewing supplies).
Step 1: Cut Out Rectangles
Cut rectangles out of your two shirts- two identical rectangles per shirt.
The dimensions between the two shirts' rectangles should be the same on three sides, but the rectangles from one of the shirts should be a little taller (my gray one was about an inch taller).
The taller fabric, which I will henceforth refer to as the gray fabric, will be the outside for the drawstring pouch.
The shorter fabric, which I will henceforth refer to as the red fabric, will be the outside for the backpack.