Determine positions of dowel pockets, and mark them on back of shade with a disappearing-ink pen. Pockets should be evenly spaced at intervals of 8 to 12 inches (depending on how wide you want the pleats to be). To determine position of bottom pocket, divide size of intervals by 2, and add 1 (for example, if you're spacing dowels 12 inches apart, the bottom pocket should be 7 inches from the bottom of the shade). The top pocket should be at least 10 inches from the top. Begin measuring and marking your intervals from the bottom, and don't worry about the precise size of the top interval. Sew cotton strips as shown: Fold in half lengthwise, wrong sides together; press. Machine-stitch a 3/8-inch double hem on the long edge. At one end, fold, press, and machine-stitch a 3/8-inch double hem.