This is kind of a confusing way to go about getting advice.
First - chances are, you're overthinking this. Want to know the easiest and most efficient way to do a switch/reset a trick when walking between groups or tables? Just .... switch the cards or reset the trick. Literally, just do it, as you walk over to the table or when you first get there, while casually chatting with the people. If you have a card in your pocket you need to switch for a card in the deck, just do that. Take the card from your pocket, put it where it goes, take the card out of the deck and put it where it needs to be. If you don't make a big deal out of it, no one will ever notice.
Second - If you really want a specific description, then give us a detailed description of what you're trying to do. Where are the cards going to be when you are doing this? Where do they need to be? What are the restrictions?
First off, I think the best thing to do would really be the casual approach, as you said. Just switch it in front of them.
The specifics for this:
I do an original trick (or the reinvention of one without my knowledge of the first one existing) where a back design of a deck changes color in the spectators hands, except for one card (their selected card), which does not change color. I am left with a full red deck, and 1 blue card (which was there car. I have been experimenting with Angle Z and have thought "this effect would be great if I do it with a selected card that they have already seen/handled". I think it will work really well after the deck color change. So I want to switch out there card for the Angle Z "gaff" in between the tricks as I talk.
The gaff cannot already be in the deck, since the deck color change takes place in the spectator's hands, and they spread through it without me ever touching the cards (not to mention the color difference). Therefore, the switch cannot happen using the deck.
I think I have 2 (and a half) options:
1) Keep the gaff in my pocket, and get it into a cop. As I take the deck back after the effect, I put the gaff on the bottom. I then take the selection from the previous trick, and put it on top of the deck. As I put the deck in my pocket, I simply come out with the gaff.
1.5) The problem comes in the fact that since the color change happens in the tuck case, and in the spectator's hands, it might be weird to put the cards in my pocket without the case. So I could learn and do a bottom change, then put the cards in the box and then put them in my pocket.
2) This is probably what I will do, but need someone's opinion as to how to make it as smooth as possible. I put the red cards in the box, I put the blue selected card on top of the box. I go to put it in my pocket, and as I come back, I pull out the gaff card from the same pocket. I was talking the whole time then say "you know what, here let me show you another trick" (should I put "with that card"?) or something along those lines.
but I don't like exposure.
