Why not do a Wayne Dobson magician force? I recently did Invisble Deck routine to my girlfriend. Told her to pick up any two suits and hand them to me, she handed me Hearts and Clubs(perfect as I forced 7 Hearts), we got rid of diamonds and spades after that. Then I asked her to pick one either hearts or clubs, she picked hearts(perfect), then asked her to pick any card in the hearts and put it upside down in my invisible pack. Asked her what her card was.. she said 7(PERFECT!) in my real deck I had the 7 of Hearts upside down.
although it's a great way for an effect, it's wayyyyy too slo for the effects i have in mind. The thing is, i'd like to ask people for a card instead of asking them to pick a card.
For now, i've been using the index deck from Daniel Madison which has been working great. But it uses pocket space which i don't like.