Here is a small walkthrough of how to do a basic sleight of hand card trick.

Start by having your participant pick a card at random.

Show the participant their card and that there are no duplicates in your other hand.

This is where the trick happens: when you put the cards back on top of the deck (making the participant think their card is still in the middle) make sure you slide the card over to the other hand when you flip them back on top so now their card is actually on top of the deck.

Now every slight of hand trick needs a small distraction, this is just a small shuffling trick to keep their eyes distracted. You can do anything you would like as long as the card stays on top.

At this point all you have to do is snap your figures and flip over top card revealing their card. Enjoy