Announce your open prediction, which is secretly at the face of deck.
Commence typical OP dealing procedure, stud dealing into a neat faceup packet on the table. When they stop you, deal the next card facedown, but sidejogged to the right. Deal a few more cards faceup. Now turn the deck faceup, end for end. In the process, execute that old reverse, where the face card remains in the left hand, kinda sorta copped, and the deck is placed on top of it. The OP is now facedown at the bottom of the faceup deck.
Deal a few more cards from the face. Then spread the deck in the hands, ostensibly to expediently show the OP is nowhere to be found. As you square back up, prepare a block of about twelve cards at the bottom (rear) for a VT. (“VT” is secret code for Vernon Transfer. I’m abbreviating it so laymen don’t find this post and learn a secret by accident.) Under cover of spreading the tabled packet, VT the block onto the cards. Thanks to the Chucky Nyquist, the sidejogged card will vanish under the spread and the facedown OP will blink into view. It’s a fairly smooth switch. I think.
Food for thought.