The single card prediction is a holy grail to be sought after. Rick Lax gives his solution in his creation, Master Piece. One card is in play, they name a card initially your prediction doesn’t match. The magician then tears up the card and hands the participant a piece. That piece then changes in the hands of the participant.
This is very easy to do and only one card is in play. You will need a way to dispose of the pieces but other than that you could perform this without anything else. A card is destroyed in each performance so refills will be required. The deck you receive has 52 gaffs anyways, that will last quite a while for most.
This is an excellent easy to do piece of magic! Great job Rick!