Pick up the cross-stacked set of cards that you have just forced upon your volunteer. (You and the volunteer should be standing or sitting at a table across from each other.) You need to pick up the cards carefully and deliberately, making sure you cannot see any of the cards. Your skills of redirect are very important here. As you slowly pick up the stack, ask leading questions of your volunteer as to how much he shuffled the deck and how careful he was to not show you the cards and how he cut them and placed them on the table. You are essentially making the volunteer take ownership of the perceived control of the trick.
Hold the deck out in front of yourself, about chest high to your volunteer. Carefully holding the two stacks, which are sandwiching the third stack with the forced card, you offer him the center stack.
Ask the volunteer if he's ready. Tell him to pull out that center stack and look at the bottom card. This is the card you saw as he shuffled them. If your volunteer had time to think and analyze what just happened in the last few minutes, he might realize you saw this card. This is why your redirect is so important. The redirect takes his mind away from analyzing the trick to thinking about the thoughts you planted in his head of how well he shuffled and mixed the deck and had control of the situation.
Tell your volunteer to put his stack back into the stack of all the cards. He can shuffle or otherwise, do what he wants with the cards. This is where your creativity comes into play.
Set the stage for the reveal. You can simply fan out the cards to pick, or you can "read his mind" and just pull the card out. You can whisper your prediction of what the card will be to a second volunteer. The possibilities for setting this up are endless. Typically, the better the redirect, the less elaborate the reveal needs to be.
Complete the reveal. Pull the card out of the deck, "read his mind" and tell him which card you think it was, or have the second volunteer reveal your prediction for you. With an excellent redirect, you'll appear to be a freak of nature.