theory11 — Magic Tricks & the World's Finest Playing Cards
I think it's more a question of time than tricks to be honest. I perform effects that by themselves take between one minute and thirty minutes.
As mentioned though, for the love of god, do not do all card tricks and do not open with a pick a card trick. This is one mistake that a lot of beginners make.
But I like Pick a Card Tricks
Everyone's been right so far, I'll give my two cents to add on.
I think it's been helpful for me to have 8 or so tricks in my head. A few card, some coin, and some other prop magic (bills, straws, silverware, rubber bands...) and then one or two heavy hitters (that I will more than likely not use).
Those 8 tricks are the core of the act and I do 3-4 of them (usually prepared sets) at a table. If all is going well I can pull out a heavy hitter (Giant wooden Finger guillotine ftw!...) or one of my other tricks that would fit where I am.
It's important to have 2 different sets of magic so you can do tables that are near each other without repeating the same things they just half-way watched over their shoulders.
Time is more important than tricks (as has been pointed out) and time is dependent on more factors than most beginners take into consideration. David Stone's book Close-Up: The Real Secrets of Magic has a lot of practical advice for figuring out how to divide the time between every table and tons of other advice that you'll want to know before doing strolling/restaurant venues anyway...so buy it.
That is in my opinion a much better way to think about tricks! Think about them in terms of routines. Think about them as a pool of effects, that you can vary according to the demands of the performance, and to other more important factors such as time!
Depends on how much time you have. But generally it's better to have maybe 2-3 routines. Anything more and you're bound to annoy and bore people to death. No matter how talented you are. Specially if you are working in an area where people are drinking. Once Booze enter the equation, then their attention span tends to drop sharply.