Do one or two sleight of hand routines that every magician knows and then do either a key-card principle trick or maybe even use a marked deck.
If the first few routines are very refined and perfectly executed they'll be looking for methods that don't exist in the second set of magic. It's like a story I ready about Harry Lorayne when he was teaching his memory courses. He would 'memorize' a deck of cards in front of his students (actually using a stack) and then provide a demonstration of which one was missing by naming them before he dealt them and when one wasn't right he knew it was the one.
When he did this it was easy for him to get away with using a stack because everyone thought he was using his genuine memory. Given his abilities he could easily use pure memory, but it's easier to appear to.
I can't remember where I read this, but the magician who wrote it said he does the same (or similar) feat with genuine memory techniques because it would be harder for him to fake it. He's known as a sleight of hand card man. Harry Lorayne, who is an accomplished magician, isn't known for his magical knowledge, but his memory abilities.
Magicians are usually fooled by any method that spectators would incorrectly guess about other tricks. If a spectator says 'It's up his sleeve, or he palmed it, or it's a marked deck' most of the magicians would laugh and know it was different. If you actually used key cards and marked decks then magicians will usually be looking for the sleights.
I'll leave you with this ::
Teller in Egypt