On my main commuter I mounted the forward 180-degree flasher on the fork so light dances off the spokes. On my old roadbike I did the same but also with the red, rear 180-degree light which I mounted to the left seat stay (the tube that runs from the rear hub to the seat, effectively the rear fork). On my MTB based commuter I used to put three orange glow-sticks in the spokes. It looked like the wheels were on fire.

Speaking of which: Go 2min and 14sec in