I will share with you a force that I (believe I) made up. But who knows, perhaps it was created by someone else centuries ago and I did not know of it. In any event, I think it appears quite fair and is deceptive. If you like it or it suits you, please feel free to use it. Let's say, for example, that the card you want to force is the queen of hearts. I spread the deck and look for the force card, and cut it to the top of the deck. Or, alternatively you could get a break below the card and do a double undercut to get it to the top. Any way that you can casually get it on top without being obvious or creating suspicion is fine.
Then, tell your spectator, "I would like you to name a random number, not to small and not to large, say, between 5 and 20." Let's say for example, that they name the number 7. Say, "OK, I am going to have you select a random card using the number you've chosen, the number 7 - let me demonstrate what I would like you to do in a moment. You will count down from the top of the deck, dealing one card for each number, like this: 1, 2, 3, 4, 5, 6, 7, and the 7th card will be your card." (As you say this, you are dealing seven cards from the top onto the table or into their hand, one at a time, each card being placed upon the one dealt before it. Then you pick up the packet of cards you just dealt and place it back on top of the deck. So, at the end of your demonstration, the card you want to force - in this case the Queen of Hearts - is now 7th from the top.) Then, you say, "But before I have you do this, let's mix up the cards to be sure they are in a random order and no one can know which card is which." With that, you do an overhand jog shuffle, injogging the first card, shuffling off, then cutting all the cards below the injogged card to the top. You could make that final cut in your hands, to the table, or get a break below the injogged card and even cut small packets to the table - the end result will be the same. Thanks to this devious procedure, when you hand the spectator the deck to deal down to the 7th card, all seems fair, but everything is perfectly arranged so that the 7th card will in fact be the force card.