This is a simple card trick called the "Card Sharp". It will all be explained in the video in the first step. The trick itself is very simple and requires no gimmicks or setups.
(Sorry about the bad quality pictures)
Step 1: Watch the Video
Watch the below video on how to do the trick:
After you have finished watching the video please post feedback.
Step 2: Or Follow These Written Instructions
First of all you take your deck and get all 13 cards of one suit. Lay them down in numerical order like the the picture below. Make sure your spectator knows the cards are in this order and collect the cards up, obviously still in the same order and flip the cards over so that the cards are face down (make sure the ace is on the top).
Step 3: Deal or Dip?
Tell the spectator that the cards need to be shuffled. Say that if they say deal you will just put the top card down on the ground (making a pile eventually) and if they say dip that you will take the top card, put it under the 2nd card and put them both down on the pile. If you still don't understand, as an example the spectator could say "Deal, Dip, Dip, Deal, Deal, Deal, Dip, Deal, Dip" and you follow the actiosn.
Step 4: Do It Again!
Repeat the last step. A good excuse is that it needs to be shuffled even more.
Step 5: The Magic Part
Explain to that spectator that you are magic and that you have told the cards where to go even though the spectator has chosen how to shuffle the cards (or you can simply tell them that they're terrible shufflers).
Turn the deck over and spread the cards out in a line.
The cards are in the same order they started out in!