Start by making your pocket flap. Fold the pocket flap piece right sides together so you have a rectangle that is 3.5×9 inches.
Sew up the side and clip the corners. Turn right side out.
Fold one of the 10 inch sides under a 1/2 inch and sew down.
Then lay the pocket with the unsewn side lined up with the center of the top edge of the back piece. Fold under the 10 inch unsewn side and the 9 inch side that is on NOT on the edge of the back piece. Sew along both edges of the pocket.
Position the pocket flap in the center of the pocket lining up the raw edges with the edge of the back piece.
Lay the rip stop on top of the back piece (on the right side, the pocket side). Sew around all the edges leaving a 3 inch hole.
Turn right side out and with the pocket flap open top stitch around all edges 1/4 inch closing up the hole.
Add your snap to both the pocket and the flap.
Fill with WaterWipes, a few diapers, and get ready to change some stinky baby bums ;)