Step 8: Trim the excess fabric and clip the corners. BE SURE TO LEAVE THE OPEN GAP FABRIC ALONE. This will be tucked inside later, just like you did on your bookmark.
Step 9: Turn the project right side out and push out the corners with a blunt object.
Step 10: Tuck in the extra two flaps at the opening and press the entire coaster flat.
Step 11: With a 1/8th seam allowance, topstitch around all four sides, backstitching at the first and last stitches.
TIP: start in the middle of one of the long edges so that you’re not trying to start on a bulky corner.