Here are 2 quilted fabric rectangles. I made a simple 9-patch, quilted it and cut it in 1/2 (13" square).
Using a short length, wide (width) zigzag stitch, make a "bar tack" on the marked line. Make sure the zipper is OPEN! You're just stitching across the coil (zipper teeth) to hold it together.
This is how it looks. Then just cut off the bit at the ends. This is why the zipper is long, you get to cut off the metal stops. You'll need to do the same thing for the bottom of the zipper. And yes - you can sew right over the coil and simply cut off the ends.
Now make a fabric zipper tab. Cut a piece of fabric ... oh, about, 3 1/2" x 5"ish. Fold 2 long raw edges to the center and then fold the piece in 1/2. You want to encase the raw edges. Slip the zipper end into the tab and stitch across. Do this for both ends. Yes, you CAN sew right over the coil!
Now ... with right sides together, simply stitch one side of the zipper to the quilted fabric. I don't use a zipper foot. I guide off the right side of a regular sewing foot and move the needle position over 2 clicks.
Place the other side of the zipper - right sides together with the other part of the bag. It's a lot easier to sew passed the zipper pull if you zip and unzip while sewing just to get by that part. Lift your presser foot and you should be able to zip/unzip as needed.
When both sides are sewn, press the zipper flat. Topstitch on the front close to the fabric edge. This keeps the zipper flat and you won't get fabric caught when zipping up your bag.
And ... here it is ... all ready to make into whatever shape bag you want. It's so much easier to put the zipper in, with tabs, working flat!
This is the back/inside - see the zipper tabs?
And here is another cute finished bag. This one is going to my sister as part of her Christmas gift. She doesn't have a computer and the word "blog" ... means nothing to her.