Iron on the fusible interfacing onto the back of the main fabric with a hot dry iron
Lay the fabrics right sides facing together and sew down both sides of the fabric on the short side
Turn the bag right sides facing out and then press the edges that have been sewn.
I used fabric tac to glue the zipper ontop of the sew edge, using a zipper foot sew along the zipper to secure it to the bag, do the same to the other side, you will need to open the zipper to sew it effectively
Slice down the sides of the bag to square up edges and clip off the rest of the zipper
Keep the bag right sides facing out and sew down the raw edges of the bag with a 1/4″ seam allowance
Flip the bag inside out and sew down the same sides of the bag again with a 1/2″ seam allowance
This is a french seam and it will hide all the raw edges and create a finished pouch