This was easy for me. Take two sharpened pencil points, cut them off at an angle, then paint them chrome silver. Then glue them to a strip of sheet metal (also painted chrome silver), bent to fit around the toe of each shoe. Drill two holes into each piece of metal, then screw them in with wood screws into the rubber soles. For added effect, I added modeling putty to elimate the screw head grooves (making them look bolted on). Just be sure not to make the pencil points too long, otherwise they *will* get caught on the floor when you walk. It also might be a good idea to clip the tips of the pencil points, since being too sharp can also cause them to get caught on carpeted floors (I speak from experience).
Good luck!