Things You'll Need
Instructions
Cut two rectangles from fabric, about the size that you want your finished bag to be. Almost any type of fabric will work.
Place the two rectangles on top of each other. If the fabric has a nice side and a not-so-nice side, put the nice sides, which are also called "right" sides, together facing each other.
Put the thread through the needle and pull until the two ends are about the same length. Knot the ends together. Using a doubled thread such as this will make the stitching stronger.
Start about 1/2 inch from one corner of the fabric rectangles ̵1; 1/2 inch from the edge in both directions. Sew up and down through the two pieces, staying 1/2 inch from the edge. Sew around three sides of the rectangles, stopping about 1/2 inch from the last edge. Make a knot and cut the thread off. The fourth side, which will be the opening of the bag, will not be sewed closed.
Fold the un-sewed edge of just the top piece of fabric down about 1/2 inch. Make a new knot in your thread, and sew this folded edge down to the fabric below it. Sew as far away from the fold as possible because the string has to go through this part of the bag above the seam. Be careful not to sew through both rectangles, though. Turn the bag over and repeat this process on the other side.
Cut a fairly long piece of string and tie it securely to the safety pin. Insert the safety pin in the channel you just made and push it through. The safety pin is easier to grab through fabric than the string. When it comes out the other end, turn the bag over again and push the pin and string through the channel on the other side.
Untie the string from the safety pin. Cut it to the length you want, and knot the ends. Turn the bag inside out, which, because you sewed it inside out will actually make it right side out. If you want, you can iron your bag to make it look a little crisper.