i perform at school alot, people expect me to show them a new trick every day, I do not perform infront of more than three people. Its best only to show to girls because guys are cocky and get very jealous and try every way to figure the trick out. DO NOT show a trick more than once. At school people will look from every possible angle. If somebody does say how its done, tell them "ok lets see you do it" and never show them the trick again no matter how much they ask
I'm going to have to contradict on a few things, though I agree on being stubborn about repetition.
Well, when I was at school I performed very rarely, and then to about half a class, all boys (it was a boys' school), semi-surrounded. I would NEVER say 'ok let's see you do it' because you are making a confrontational challenge of it, which isn't what you want, and there is always a danger they will be able to do it well enough to demonstrate that their concept works. There were some scarily clever people in my classes, and it would have been arrogant to assume they were wrong even if my technique had been perfect. Sometimes people will say they knew how something was done, or throw out a theory. To 'I know how that's done!' I would just meet their eye a moment, nod slightly to acknowledge that they may indeed know, and move on. To a theory, I would either ignore it, or, if it's quite a good one (correct or incorrect) say 'Hmm. I see that could work, yes.'
Claiming to be the real thing around people that know you is foolishness, as is becoming a regular 'trick monkey'. The secret is to do it infrequently enough that it feels like a bit of a treat. This will get you more respect when performing.