How to perform the overhand shuffle:
1. To retain the top card in its exact position after thoroughly shuffling the deck
Firstly, take hold of the pack with a relaxed but firm grip face down in the left-hand (presume you are right-handed) and holding it at an angle of roughly 45° towards the right. Next, led the pack with the right hand keeping the top card in the left hand by means of applying a little pressure with the left thumb. Then, shuffle the all the cards on top of this one.
Next, raise the whole deck with the right hand and proceed to shuffle off each and every card into the left hand right down to the last card which you will drop on the top of the others. By means of this seemingly innocent double shuffle, you will have an effect returned the original top card exactly to its original position in the pack.
2. To control a selected card placed on the top of the pack
Holding the pack in the left-hand, once again lift it with the right hand this time apply a little pressure on the bottom card with a left fingers keeping it in place and at the same time as in 1 above, draw off the top card with the left thumb. In doing this, the top card will fall on the bottom card in the left-hand and all the cards in the right-hand can now be shuffled freely on top of the two in the left-hand.
You will have noted that the original top card of the pack is now second from the bottom and because of this fact you are able to turn the pack over and show that the bottom card is an indifferent one. You can also turn the cards once again face down and show a few cards from the top to also be indifferent cards.
Now for the clever bit! Shuffle once again and this time retain the bottom card by the pressure of the left fingers. As you shuffle the cards on the right hand to the left you will be aware that the very last card of the right-hand portion of the pack will be the original top card and so you can shuffle freely until it is the only card remaining in your right hand whereby you can drop it on top of the pack in the left-hand.