3. If you have the card you want to control on top of the pack then one good way of keeping it there very easily is to turn the deck over some of the cards are face up and to shuffle the normally except that as in 1 above the left-hand fingers keep a grip on what is the top card thus keeping it in position. Your excuse the shuffling the deck face up can be that you want to show clearly that you are thoroughly mixing the cards.
4. For a more advanced and professional overhand shuffle, let's say for example that you have the ace of hearts on top of the deck and that you want to shuffle the deck keeping it in the same position. Here's how you do it:
Begin the shuffle as normal pulling a few cards off with the left thumb, dropping them into your palm as you bring the main part of the pack over. Next you drag off only one card from the top of the main pack with your left thumb sliding it onto the cards in your left palm only this time using the left thumb, you pull the card about half an inch towards your body. This is called in jogging the card and this in jogged card is now above your ace of hearts. You then continue to shuffle the cards on top of the stack until they're all in the left-hand. From your angle you can see the in jogged card sticking out but your spectator and audience cannot. What you do next is to undercut the cards again by pushing upwards with the right thumb on the underside of the in jogged card creating a break. It is now relatively straightforward to shuffle all of the cards above the break into the left-hand palm and then to drop the rest of the cards on top. In this way the ace of hearts is retained on top of the pack.
This false shuffle will work to retain not just one but a few cards on top of the pack was the obviously you just have to make sure that the first batch of cards pulled over with your left thumb is big enough to include all the cards you wish to retain. Don't be put off if you find this false shuffle a little difficult -- it does take a little practice but it's well worth the effort that you put into it.