Here I have a big blue pocket I'm wanting to put inside a tote bag I'm making. I want it to have a zipper enclosure at the top. Here we go!
Step 1: Pin one side of your zipper directly to the top of your pocket.
Step 2: Sew the one side of your zipper to the top of your pocket--right on the front of it! Both the right side of your fabric, and the right side of your zipper should be facing you.
Step 3: Pin the pocket where you want to sew it.
Step 4: Sew the top half of the zipper down to the fabric you are attaching your pocket too.
Step 5: If necessary, sew the sides of your pocket down. I didn't need to do this because this pocket is the same width of my bag and will be sewn into the side seams of the completed bag.
Step 6: Enjoy your easy-peasy zippered pocket.