Align one corner of the shade cloth against the cable. If possible, have a friend hold the other end. If not, temporarily clip it in place with clothespins or clamps.
Place a butterfly clip over the shade cloth and cable, so the cable fits into the butterfly clip's center groove. The teeth on the butterfly clamp hold tight to both sides of the fabric.
Fold the butterfly clip over, so it clamps onto the upper-side of the shade cloth's corner. The shade cloth should not be covering the cable.
Clip the other clip to the other corner of the shade cloth.
Evenly space additional butterfly clips between the two corner clips, such a clip is placed at least every 2 feet. The completed assembly should allow the shade cloth to slide along the cable for times when shade isn't required. For an immovable, taut cover, add clips to side cables as well.