Here is a tutorial for turning a tshirt or tank top into a drawstring beach bag. I have had this shirt in my stash for a while, I just loved the bright colors, but I would never wear it as a shirt.
Here is a way to repurpose those nostalgic shirts hiding in your drawers.
1. Grab a tshirt or tank top you want to reconstruct.
2. Cut out the front and back of your bag. I made mine a square at first, but then made it more of a trapezoid instead. (I didn't have much trim room on the top of the shirt)
3. My shirt didn't have enough space for the top edge, so I cut out two contrasting pieces.
4. Make the top piece half an inch longer than the top edges lengthwise.
5. Hem the two short edges of each green piece. This way the top piece is the same length as the bag body.
6. Fold the top small piece in half lengthwise, wrong sides together. Sew this to the top edge of your main piece, right sides together. Do this for both the front and back pieces. This will be the casing for your straps.
7. Top stitch for a clean finish.
8. Cut out two pieces of cord, ribbon, or fabric that are each 54 inches long. (27 inches when folded in half)
9. Sew the bottom edges of the bag together. Then feed each of your cords through each of the casings you created on the short edges. (Take one end of a cord, attach a safety pin to one end and feed it through the (green) top casing. Repeat on other side with other cord.))
Once the cords are fed through the casings, aim the majority towards to the interior of the bag. (So the cords end up on the outside/right sides in the end.)
10. Sew up the sides of the bag, right sides together. Do not sew the top corners together, otherwise your drawstrings won't be able to scrunch.
11. Place the raw ends of the cords at the bottom corners of the bag. I backstitched over them to be safe.
12. Here is the bag inside out completely sewn. Trim any access.