Holy cow! If we nixed EVERY thing in this thread from our patter, we'd be doing our act as mutes!

But seriously folks (Hey, there's one, but it applies more to comedians) so good evening ladies and germs.

ANYWAY, I think some of these lines mentioned here are definitely trite or hackneyed, but a lot of it depends on how many magicians your spectator (or shall we say participant?) has seen. 

I've ran into many folks who have told me that my performance was the first actual live performance they had ever witnessed. So for these folks, ALL the lines are fresh.

I suppose in the end, you have to play it by ear and try to be sensitive to each person's body language and other verbal and non-verbal clues, etc. Taylor your patter and performance to the situation at hand. 

Years of performing EXPERIENCE and years of dealing with people -people handling skills- are definitely the order of the day.

For some reason I hate the term "magic trick". It sounds childish to me, and makes me feel like I'm 12 again. I don't have a better term, and it's probably just me, but for some reason I don't prefer that term.

How did you do that???

Can you keep a secret??

So can I!

I doubt most people have seen enough magic to recognize these lines as hackneyed. Corny, yes. Hackneyed, no.

I've seen a decently well known magician say this as patter on stage. He was a comedy act, but it still didn't feel right.

Virtually every street magician these days:
"Can I just show you something"
No you can't you pervert!
or
"Let me just try something here"
TRY something? What, like you haven't already practised this for hours and hours in your bedroom?

Watch as I make your 100 pound note disappear...do you have a diamond ring on you by any chance?

- Yazz

When mentalists keep saying "Be honest...".

"Would it be impressive if..."

"Under test conditions..."

All hacky lines

Any "Play-by-play" patter that follows "I'll just...."

"I'll just shuffle the deck and put it here on the table...now I will cut the cards and have you take one...." AAAAHHHHHH! We can see what you are doing - no need for the obvious exposition! 5 minutes on YouTube will show you how wide spread the blight of PBP patter is. It's depressing.