Zippers can be soooo tricky. They like to move around when you sew, even if you pin.
Below is a video link tutorial on how to install a side panel zipper into a bag, or
anywhere you want to instal a zipper.
The bag I am demonstrating with is Swoon India-small size (affiliate link).
Also, ignore my ignorance of shapes. Anytime I say a shape name, I am referring to the rectangle.
My mind was distracted by not screwing up the video. I can't seem to get anything perfect.
Here is what the finished bag looked like. Purdy little girl.
I also have other Swoon India bags in the Etsy shop!