Now, Either use the pattern to cut out belt pieces, or just cut out a couple rectangles of the satin-y back fabric. Mine are roughly 11" and 12" long, by 3.25" tall. (Different sizes for buckle / strap.) Sew them together at one end, and down the long side. Trim, notching the corner, and flip inside-out. (Use a pencil or something to help push it through). Now, sew it loosely (no backstitching) to the back of the back, at the edge, and 5" closer to the center, for each side. (This is called "basting," and you can just pin it too, but you're going to be handling it a lot, and you don't want pins. Ow.