Easy Card Trick Number 1 : First perform a secret operation i.e. flip the bottom card of the deck. Now, in front of the audience, fan the cards in such a way that the audience cannot see the flipped card. Ask one person to pick a card from the deck.
While he/she is looking at his card, flip the deck again and as the bottom card has been flipped, it will look like the top of the deck.
Now keep on talking and slowly flip the bottom card so that it will be the flipped card that will get chosen. As the audience member puts the chosen card back into the deck, it will be the only card which will be upside-down in the entire deck.
Now you can act and shuffle the cards as long as you want and still be able to find the chosen card as it's the only one facing upside-down.