Invisible Coin is all you need and it is really easy to set up

Daniel Garcia Orange

The signed card can be given away as a souvenir

when he opens it we can see Santa Claus holding a letter and Rudolph and his red nose by his side

There are many of possibilities

Triple Vision trick - David Regal Jim and MacGregor Invisible Coin is all youA Test Condition Impossibility! EFFECT: When the magician notices that he's missing a few cards from his blue backed deck, a few cards are randomly chosen by a spectator from a red backed deck and added to the blue deck. When the magician discovers the missing blue backed cards, they match the red backed cards chosen by the spectator! Different Cards Can Be Used Every Time The Effect Is Performed A Self Working Killer Effect from David's Magic Castle