Control the controllables.
* I'd pick someone with whom you know you will be able to communicate with easily.
* Make sure you are fresh and clean when you turn up. Even then, show willing and have a quick shower to prove it.
* Read the punting wiki
External Link/Members Only Also when you hand over the money, think nothing more of it. It's gone. Everything you get after that point is a bonus. If you fixate on getting your monies worth you won't enjoy whats going on in front of you.
Finally, they won't give two bits about your cock size. They will want to see you again if you are clean, polite and don't haggle or weird them out.
Oh and don't fall foul of EAS and get a punting phone. You may think that there is no danger or no one to care about your escapades, but your life can change.