Work it with a mentalist angle. Separate the cards into a face up and face down, shuffle, deal out two piles while explaining that you can read their mind. Tha

Work it with a mentalist angle. Separate the cards into a face up and face down, shuffle, deal out two piles while explaining that you can read their mind. That you can pull numbers right out of their head. Have them pick a pile. Slide it over to them and slide one under the table while telling them so you can't see what you're doing. But really it's because they can't see what you're doing. Tell them to go through their pile and count the number of face up and face down cards. But don't tell you. Emphasize that they shouldn't tell you the numbers. Once they have the counts, stare at them, make some jokes about what they're thinking. Then shuffle the cards around under the table a bit. Make it look like you're thinking about what you're doing, mutter, "yes, yes, no, up, down" etc. Then after a few seconds, say you got it and do the reveal. Bonus, if they flipped their deck before counting and therefore the counts are backwards, you can go "ta-da" and flip your deck in front of their face, working the misfire as a false reveal.