Hollow glass globes were once used to keep fishing nets afloat. Sometimes these floats would break free to wash up on beaches. In Europe, superstition once held that such floats could ward off curses, leading to the custom of displaying floats, nicknamed "witch balls," in front of the home. This custom was later carried to America. Glass floats have fallen out of use, but you can still find both antique and replica floats. You can turn these into ornaments by knotting nets for them.
Measure the diameter of your float. Cut eight lengths of cord or twine, each ten times this diameter. Seal the ends by melting or gluing.
Lay the cords on the table in an X, with one group of four cords crossing the other so each arm of the X has four strands. Take the left lower group of strands and fold it so it lies horizontally, making an open loop on top of the other four strands.
Fold the lower half of the bottom four strands over the loop in the top four. Fold the upper-right arm of the X-shape down over both halves of the bottom four strands. Fold the upper left arm of the original X-shape over the segment that was the upper-right arm and tuck it through the first loop you made. You should now have a secure knot in the middle of 16 strands. This is called a lanyard knot.
Fix the lanyard knot to the base of the glass float with masking tape. Arrange the 16 strands into eight pairs. Tie a loose overhand knot in one of the pairs. Take the other strand and feed it through the overhand knot. Tie a second overhand knot in the other strand, and put the end of the first strand through this knot. Tighten both knots so they fit snugly together; this is a fisherman's knot. Repeat for each pair, one inch from the lanyard knot.
Pair up the cords again, taking one from each of the previous pairs and matching it with one from the adjacent pair. Tie another row of fisherman's knots one inch below the first. Ensure the net is snug around the float. Repeat, securing the knots with masking tape as you go, until the float is covered.
Arrange the threads into groups of four and tie three lanyard knots. Slip the ring over all the cords, two inches from the top lanyard knot. Tie all the strands to the ring.
Cut a 36-inch length of cord. Wrap the cords firmly with this and tie it off.