When I am done with a trick deck, I use the "WOW" moment to make my move. There is always a confusion/ amazement or wow moment at the climax of a trick, and THEN someone will ask to see the deck. They won't think that you're about to put the deck away just yet.
When you do, this is usually when someone will say, "Wait a second, let me see that deck..." I love it when they do. Cause then I just take the deck back out and give it to them. (Of course its an normal deck).
What do you guys think? Unless the guy is reeally a wisecrack, he won't say, "maybe you just switched decks... what else do you have in that pocket? " I just say, nothing just this, and I pull out my next trick like a hot rod or nickels to dimes, you know something that will be examinable at the end.
If you use this method of moving ahead to an examinable trick, they are like fish mesmorized by a shiny object, they forget about the last thing and just watch intently at the next! Always finished with something examinable.
NOTE: don't wear tight jeans, the switch deck will obviously show through.