DIY Jump Cups - LOVE these! So simple and SO SMART! Two 2-inch-long pieces of 2x2" scrap with holes drilled for the rope. One galvanized spike with the end cut or sanded off. You could also use carriage bolts. Braided nylon rope, about 1/8", tied in a circular loop. About 24 inches long. Burn the ends to prevent fraying.