Playing Crazyhouse OTB I was playing Crazyhouse online on Lichess and I wondered how to play OTB, namely how to change the color of a captured piece.
I came up with 2 methods.

Exchange the captured piece for another of a separate chess set, picking the opposite color.

Pieces are 2d cards, with the Black version of the piece on one side and White on the other.]3


Does anyone know better methods?
Shogi also called "Japanese Chess" use the crazyhouse mechanics as well. They have one-colored  (flat) pieces that always face in one direction. If you capture a piece and bring it back into play you just let it face towards your opponent.