My go-to trick is one from the Michael Ammar video "Easy to Master Card Miracles #1". Any ordinary deck, even a borrowed deck, will do, though a deck with the same edge colors on the face and back of each card is better, and a stripper deck or a subtle one-way back design insures you can't screw it up and the spectator can't mess you up by intentionally claiming the wrong card as their own. I forgot the name, but I perform it like this.
I spread the deck and have the spectator choose a card. They remember it and I replace it into the deck, shuffling it away using three methods: first Hindu, then overhand, then riffle. I then split the deck in half, and place each half up to my ear in turn, putting on my face an expression of intent listening. I then declare that the card is in one of the two halves, and I hand the other face down for the spectator to hold firmly in their palm.
I riffle through my half a bit, listening for the card, and start rearranging the deck into packets between the fingers of one hand. Eventually I slide five cards one at a time off the deck from one hand to the next.
I tell the spectator that I can hear that their card is one of the five cards I'm holding in one hand, while the rest of the packet is held in the other. But I also say that sometimes the cards do try to trick me, so I ask for their help. I tell them that I'm going to turn the cards over and show them one at a time, and that after they've seen all five, to tell me if their card is one of them or not without revealing which. I flip over the five cards face up on top of the face-down packet and slide cards from one hand to the other while counting them off. (If done correctly, the answer is usually yes!)
At this point I hand over the remainder of the deck, only holding the five cards. I recount them, insuring that there are still five cards there. Then, depending on how I'm equipped at a given moment, I'll either use a Pure Smoke puff on the cards or I'll hold them to the spectator's ear, asking them to listen and see if they can hear the cards, at which point I bend them slightly and pop them back, making a small, audible click.
Now I count out the five cards again, face down, only to discover that I'm only holding four. I turn the cards over in a fan and ask if their card is among them - the answer (again, if done correctly!) is no. At that point, I tell them to put the packet down on a table and spread them across - or if no table is available, I ask them to spread them face down one at a time. Whichever method they use, they eventually discover one face-up card mixed in with the face-down pack - and it's their card.
I've gotten very good at the trick, though I can see places where there's room for improvement. Of course, there's some controlling used in the shuffles so I know where the card is, and the second and third five-card counts are Biddle counts. This was the trick I did for David Blaine's assistant, with him and Asi Wind watching me; Asi said he does the same trick (with different patter, I'm sure) but that I did it pretty well. Asi is a popular Israeli magician based in New York, and he performs often as part of a live show series called Monday Night Magic. They do dinner shows on Sunday night and theater shows on Monday nights, with a different roster of magicians each time. I haven't had the privilege of checking them out yet, though - the tickets aren't cheap and I do work those nights.
So, as I'm fond of saying in the hospital, "Next victim - er, I mean 'patient'..."