18. With the bag still inside out, pull the corners apart at the notches until you can line up the side seams and bottom seams, right sides facing, at all four corners.
19. Pin the corners together, then sew across each one with a 1/2" seam.
20. Turn the bag right side out through the opening in the lining, then stitch the opening closed. Tuck the lining down into the pouch.
Bag #2, all done!