"I started at the middle and sewed to the end using a zigzag stitch. As I sewed I pulled the elastic quite tightly while I let the denim layer feed through the machine normally. Then I did the same thing again. I started in the middle and sewed to the other edge. This made it so that the elastic was centered and I didn't stitch throught the belt loops on the other side. Lastly I did one stitch in the middle, also making sure not to stitch through the belt loops."