STEP 2: Press all selvedges of the seams to the right side. Flip the piece over to the right side and use your contrasting thread to topstitch 1/8" directly to the left of the seam. This strengthens each seam, keeps the selvedge/seam allowance tidy, and adds sophistication to the outside of the bag. A zipper foot works wonderfully to guide the needle straight down the seam, but it isn’t necessary.
Photo Courtesy John Wiley & Sons, Inc.