I needed to replace my bicycle's cassette, but I couldn't find my chain whip tool.
Did not work
Wrapping the cassette in a towel and trying to hold by hand (similar to this guy using a leather glove).
Did work
Putting together a makeshift chain whip with an old chain and vice grips.
(It didn't occur to me to take a photo until after, so the photo is staged, with the new cassette and chain...)