A chaotic motion, cards flying through the air, and when everything settles the chosen card is sticking from his mouth. Card to Mouth is one of the most visual card tricks ever created, and works on shockingly simple foundations.
Watch this trick in action
The technique: controlled mouth-load
The magician controls the chosen card to the top of the deck (via a force or double lift). He then fakes a 'flourish', pretending to do fancy card manipulation. During that chaos he rapidly slips the top card between his lips.
The mouth-load happens behind his hand or during an upward motion. The cards in the air do the rest: they pull all attention. When the spectator looks back, the card is already in position.
The psychology: chaos as cover
When motion fills the air, the brain switches to 'motion tracking'. Quick movements, especially upward, grab attention because they were evolutionarily important (falling objects, flying predators). The magician ensures the hand-to-mouth move is never the most interesting movement at any moment.
Then the unexpected location works in its favour. The brain seeks the card in hands, pockets, on the table, not in a mouth. When the reveal comes, the brain needs half a second to process. That pause makes the trick unforgettable.
Card to Mouth proves that the most visual tricks often have the simplest construction. It's about timing, not technique.