Step 5: Sewing The Bag
Pin the zipper into place on one side. Make sure the bag is folded in half on the same stitch at the top and the bottom so it's not twisted.
Sew the zipper in place and bury the stitches into the center of the cast off row. Using back stitch will give you a secure finish.
Pin and sew the zipper onto the other side.
Tuck in the zipper tails, tack them into place with a few stitches if you'd like.