I have upcycled a fabric curtain (100% polyester) into eight fabric bags which can be used for library books, class supplies, craft projects, groceries on the way home, snack run, garage sales, mall shopping, thrift stores, farmer's market, etc. I unraveled all the hemming except the top one and then trimmed the piece which was almost square into eight pieces. They were long narrow rectangles that measured approximately 17.75" x 35.5". I cut handles (3" by 18" or so) from navy (100% polyester) stash fabric. I folded them in a half inch on each side and them folded them in half and stitched up both sided using white thread to coordinate with the bag fabric. To make the bags I folded the rectangle short ends to each other at the top (right sides together) and stitched up the two sides and then zigzagged the edge of the seam allowance to finish it off nicely. I folded and pressed the top hem where needed and added the handles 5" from each side and then stitched the top hem triple stitching where the handles were. I added another line of stitching about 1/8" from the top edge again triple stitching the handles. I went back and added triple stitching in between them just on the handles. They are very secure.
Next I boxed the two bottom corners to create a bottom on my bag - I stitched about 3.5" from the corner to create a 7" bottom. I stitched the triangle I folded in to the bottom of my bag to secure it and reinforce the bottom. I stitched a 12" piece of cording with a knot at each end about 3" down from the top of the bag on one of the side seams so the bag could be folded and tied up. To tie up you simply lay the bag down handles at the top and fold the bottom so it is facing up as in the photo above. Next, fold down the handles and fold up the bottom and start rolling the bag from the side opposite the tie. Once rolled all the way to the other side you simply tie the cording around the bag to keep it neat. It was a fun project.