I cut the back piece oversize to allow for the extra seam, cut the piece in half and sew the two pieces back together starting at one end, leaving a space in the middle of the seam for turning, and finish sewing the seam. Then assemble batting first, then front and backing piece last, sew all around the outside edge. Turn through the space left in the seam on the back. It is much easier to do the blind stitch in the seam on the back than to do it on the edge of pot holder. Quilt your pot holder and top stitch around outside edge if desired. (You could stitch the closing gap by machine as part of your quilting if you didn't want to hand stitch.) Sometimes I will attach a loop or one of those plastic rings for hanging if I am using it for decorative purposes but for regular use, I prefer to leave it without any hangers.