One possibility would be a one-phase ambitious card. Have someone you know help you by selecting a card as you spread them face-down. Give them a sharpie to sign the card, and as they are doing so while the camera is on them signing the card, secretly turn the top card of the deck face up and hold a pinkie break under that card. When they give you the signed card back, place it face up on top of the face up card that you are holding the break under. If you tilt the deck back toward yourself and close to your body as you take the signed card from them and before you place it face up on top of the face up card you are holding a break underneath, they will not see anything. (You can blow on the signed card for misdirection as you take it back from them).
At this point, you have a pinky break under two face-up cards, but it appears that only the signed card is face up on top of the deck. Turn the double (the two cards as one) face down, thumb off the top (indifferent) card and insert it into the middle of the deck. It appears the signed card is lost in the middle of the deck, but it is actually face down on top. Take a small balled-up piece of flash paper and place it on the top card of the deck (which is the face down signed selection). Light the flash paper with a lighter. POOF! Slowly turn over the top card to show that it has magically come to the top. Practice it a few times, and you should have a nice mystifying visual trick of one minute or less in length. Even if you don't have or can't get flash paper, it should still be a very good quick trick. Don't underestimate the power of the ambitious card on spectators. Originally, it was just a simple stand-alone trick done only once. Just a suggestion.