Thanks all. I shall continue on- in fact, the longer I perform magic, the more a trick fails flatly, a spectator does something wrong, The more I value these experiences.
If I could give my own humble advice- I have found that practicing muscle reading (whilst immensley rewarding) is a great way to develop 'spectator control' skills- you have to make them like you and want to suceed, comunicate clearly, choose the right spectators or engineer the correct attitude, build compliance and a friendly authority but also a keep a cool head when things go wrong. All are assets which I'm sure will serve any magician.
Also, I find that getting spectators to follow irrelivavnt instructions - that is to condition them to following orders well. I heard about this in psychology studies concerning compliance and in hypnosis, but I later read about it in Richard Osterlind's 'Principles of magic'- I hadn't thought about applying it in a magical context. (I'd reccomend the book, although I disagree with aspects of his philosophy, worth reading though)
But experience is undoubtedly the best way!
I have never dropped a spectator, so far, although on that note, you can never be too careful:
http://www.youtube.com/watch?v=Glw5D7loHko
Thanks for your advice

''To go wrong in one's own way is better than to go right in another's.'' Dostoevsky's Razumihin.