In the past I am sure we all have heard that involving spectators is a great idea because it makes them more involved in the magic, and it becomes more interactive and personal. This is true. However, an often overlooked , also extremely important aspect is the fact that a spectator who is involved in anything procedural believes that procedure was fair.
For instance take the classic example where the second phase in an Ambitious Card Routine is where the spectator inserts the card in the deck. There is no doubt in their mind (assuming your double lift is convincing, and that assumes a lot for some people) that the card is certainly in the middle. After they insert the card, you should make every possible effort to display the fact there is no manipulation going on at all. Hold the deck at two fingertips. Then, give them the cards. Then let them turn the card over.
That may sound like a standard procedure, but then why do I see even some of the most acclaimed magicians like Cyril messing up this sequence. Take a look. the particular moment in question is at about 3:20.
http://www.youtube.com/watch?v=KRoqpre7nnI
It is also worth noting that all around Cyril is a decent
card handler, but I would for sure say there is a lot of
room for improvement. A few things to note on this
part of his performance...
1) He misdirects when he does his double lifts at time.
He looks a spectator in the eye and talks to them while
doing a slight. I will contend that whenever you have
both hands on the deck in a non-covert action, you
should be directing attention to it.
2) His doubles are different from his singles.
3) He spreads the cards for the spectator to insert
the card back. While this might make the insertion
easier, it requires him to have more time with both
hands on the cards. This should be prevented by
having the deck squared.
4) He does the reveal himself. As I said, whenever
possible, the spectator should have this turnover.
Which is also why I content that after the first phase
in an ACR, the spectator should always have the
turnover. This also limits me to a shorter ACR,
which I think is also the best way to go in the first
place.
All in all it is a massive neglect of audience
participation that could have heightened that
routine.
It's just something to think about when you are
considering what sleights to use in your routines.
Moral of the story...
Clean handling is great but not handling is best.