I tend to just use readily available templates for my drawstring bags, however. Two pieces of typing paper lined up length to length, for instance, make for a roughly 8″ x 10″ drawstring bag, perfect for my daughter’s ballet class uniform or the wooden pieces to her large world map puzzle. Two 4″ x 6″ photos lined up end to end make a bag that is perfect for Battleship pegs, or all my extra bobbins.
After cutting your fabric, fold it in half and line it up with the right sides together. Sew up the two long sides of your drawstring bag using any sturdy stitch that you favor, finishing the seam however you desire.