@ChristopherT,
@Bliff and
@Lord Magic - I
was being sarcastic. I don't think you should actually say any of those things in a performance. Some of these are cliche but most of them are crutches that magicians rely upon without thinking that really don't work.
Let's take them one at a time...
#7. "Do you want to change your mind?" Every time I have seen a magician use this is causes confusion among the spectator who is assisting them. They either think they picked the wrong card (or whatever) or that the magician is trying to trick them. I think the idea is that this makes the selection seem more fair but it fails. Think of it this way, if you asked someone what movie they wanted to go see (or any other question) and then asked them "do you want to change your mind?" wouldn't that seem odd? As a kicker, I can't stand the hackneyed joke that follows -- "so you will keep the mind you have." Better to set up the fairness of the selection before the selection. The best way is what I learned from Dani DaOrtiz - to give the impression that it doesn't matter what they choose.
#4. "Let's Recap What Happened." If you have to recap what happened your effect lacks clarity and is too complicated. Additionally, most magicians try to use this to create a false sense of what happened - like saying they thought of a card when it was selected from a deck. This also breaks the flow of the effect. If your audience is paying attention (because your performance is engaging) they will know what is happening. If your effect is structured clearly, the audience should realize the what what is supposed to happen a moment before your reveal.
#2. "Wouldn't it be amazing if.." This is a lot like number 4. It is a crutch for structuring and presenting an effect. I think the idea is to ask that question and then do what ever follows it. Your presentation of an effect up to that point should guide the spectators to ON THEIR OWN think of what they would want to happen and to realize the impossibility of that outcome... the moment before you do what they have concluded is impossible.
#1. "Watch." This is useful when you have nothing else to say. But, you shouldn't get in the position of having nothing else to say. If you have to tell the audience to "watch" at the height of your effect, you haven't engaged them enough.
One more for the list - "For the first time out loud, name the card you are thinking of." I actually was watching a magic show last week where the magician said that. I responded, "George." I thought that would be a good name for the card. This is even worse when the card is selected rather than actually thought of.