For me it depends on the trick and the person I'm performing for. In some cases I'd go with (a), but sometimes, when I want a really clean look I'll use one of the "invisible" controls to the top or bottom, making it seem as if all that has happened is that the card was placed in the middle of the deck, nothing more. I often prefer this because I think many laymen are well aware of "false shuffles" and may actually become more suspicious if you shuffle the deck.
Don't forget, when you are confident with palming (or if you use the UCCU), you can control the card, palm it off, then hand the spectators the deck to shuffle! Now you're really in control and looking completely fair. Woohoo!