Take an old T-shirt and turn it inside out. Draw a bag shape you like. (You can make it as small or large as you want.)
Cut through both layers so you have two identical pieces. You can leave the shirt’s hem intact or snip it off.
Stitch the two pieces together all the way around, leaving the bag’s opening untouched.
To prevent fraying, either serge or apply a narrow zigzag stitch to the edge.
Use a ruler and ballpoint pen to draw dashes across the fabric. Important: Leave room four inches from the top for your handle.
Using scissors or a rotary cutter, snip along the lines, making sure to stagger your cuts. Cut a longer slit two inches from the top—this will be your handle—and shape the sides if you wish.
Then streeeeeetch the bag.
That’s it! If you wash and dry your bag, the slits curl up a bit and it looks even better. You can use them for produce, as the name implies, or at the beach for your sandals.