If you have access to a serger, sergers work best because they will give a professional looking edge and trim all three layers to exactly the same spot. If you do not have access to a serger, you can use your regular sewing machine. See the next step for sewing machine directions.
I did my edge using both serger needles (4 threads) with all the tensions set to 4 (the normal tension setting on my machine.) I also had the stitch length set to the longest stitch length available on my machine. BE SURE TO REMOVE EACH PIN WHEN USING A SERGER. Serger’s cut the fabric as they sew and wrap the edge with thread and you DO NOT want your pins to ruin your blade.
Sergers do not have a backstitch, so instead you’ll stitch over your starting stitching for about 1 inch and then leave a long thread tail. Use a large-eyed needle to pull the thread tail through some of the stitching and trim.
Make sure your stitching went through all three layers.