This is an easy project that's so low sew that you could even do it by hand if you wanted to (or maybe "have to" because you don't have a machine).
P.S. If you're like me and hate to waste anything, check out my dog toy tutorial to use up the scraps from this project ;-)
Step 1: What you'll need:
Scissors or rotary cutter
Cutting mat (optional but very helpful)
*Note: the size of the shirt will determine the size of the bag. If you only have a large shirt and want a smaller bag, then check out the alternate instructions on Steps 2 and 3.