Here is a small refinement to the handling of a card-to-wallet routine, with the purpose of obscuring the moment of loading of the card into the wallet. I’m sure others have come up with this, as it’s such an obvious idea. So I don’t claim any originality. Think of it as a reminder of something important (not just for the Card to Wallet trick).
The basic idea here is to get the audience used to the action of the hand reaching into the jacket for the wallet. Once they are conditioned to this action, and see that nothing unusual or suspicious is happening, they will miss (or worse, ignore) the moment of actual loading.
Theoretically, if you make this move two times, and they see that nothing suspicious is happening, then they won’t notice it the third time. Again, the magic three.
To make this possible, restructure your routine. Include a (motivated) reason that allows you to reach in, remove the wallet, and then remove something from the wallet that is related to the routine. This could be a note, a piece of paper (with something written on it that is part of the presentation), or really anything that would help the routine.
The handling is as follows: You reach into your pocket, take out your wallet, open it and take out a piece of paper with your other hand. While the paper is being unfolded and shown around, the hand holding the wallet closes it and puts it back in the pocket.
Do the same thing a second time with a different object in the wallet (or put the slip of paper you took out before back in). The third time, hold the card in your palm and reach for your wallet with that hand. Take out the card, remove the wallet, and then go on to reveal the card in the sealed envelope in the wallet’s zipped compartment, etc.
This conditioning, innocent as it may seem, is a reliable strategy. It covers the moment.