I would like to play the role of Devil's Advocate.
I suggest that you perform anywhere and everywhere possible - even if your act is horrible. An act or routine is only as good as an audience says it is. The audience is the final word, because a show can't even exist without someone there to experience it - the word of the audience is law in entertainment. With that knowledge, I maintain that it is best to practice a show or routine until the sleight of hand is passable, then to promptly present it to a lay audience. For the performer himself to continue adapting the act without audience input at this point would be futile, for he may well end up making supposed improvements, only to realize that he is creating weaknesses in the eyes of the audience. More succinctly, let the audience be the director. The input of the audience is the best tool in creating a show that is well-received. Great shows are not just born after years of rehearsal in one's home.
Honestly, the best thing that I ever did for my own education in magic was taking the initiative to busk with only three effects practiced as preparation. I did this for one summer. The beginning of that summer was deplorable. By the end, I was making an average of $22 per hour on the slowest days. The most influential and innovative street magician with whom I have ever spoken is Charlie Caper (the winner of Sweden's "Got Talent" series called "Talange"), and his best advice to me was to make a show, take it out, let it get ripped to shreds, and let it rise again from the ashes. Of course, this is a process to be repeated. That is how Charlie Caper began, and now he travels all over the world, enjoying a different city or country every few weeks. As he says, "If you have a good street act, you can make a good living anywhere in the world."
No show ever becomes great without first getting torn to pieces. Louis CK can attest to this fact as well. His first experience in stand-up comedy left him so disappointed that he didn't step on a stage again for two years, but that didn't stop him becoming one of the most currently celebrated men in stand-up. "Dying" is a necessary evil that is often the most effective process in shaping great performances and performers. Every day that my friend and I went out to the streets during the first month of summer busking, we would set up our table, stand nervously, then he'd look at me and ask, "Are you ready to die?" to which I would often respond, "I have no choice. Who is ever ready to die?" and we would proceed with our shows. I have never regretted that, as tough as it was to continue after days of shows that failed even to get a clap out of sympathy.
Every performer approaches the process differently, but I have seen both sides. I spent my early years hidden away in my loft practicing every sleight I could find. After five years of that, I had the best Elmsley Count that you can imagine. When I took that Elmsley Count into the real world, five years of practice let me get away with counting five cards as four, but nothing more. When the trick was over, I got a "Good job," and a pitifully fake smile. Five years of solitary technical practice had taught me nothing about entertaining an audience. For that I continue to suffer, and it is why I am majoring in psychology and theater - I need to grind my performing teeth so that they may be as sharp as the teeth of my technique. One friend of mine suffers from the opposite side; he is always looking for an audience, and never for a mirror. He gets the, "Good job" and false smile after his routines, but for the opposite reason. He refuses to improve his technique to match his ability to engage an audience.
Let me conclude with this: A balance must be stricken between practicing and presenting a stage-worthy act. Practice is something to be done alone with a camera, but presentation can never improve without the critique of an authentic audience, as the audience is the only gauge by which one may measure art.