i approach different people in different ways. Personally, i'm a verbal/organic person so a checklist would go against the grain, and, i think, could be intimidating to a novice SMer. It's too 'matter of fact' for my style of setting up play, although i'm always upfront verbally. I don't fanny about!
i agree with kitty that email/IM reduces the embarrassment in asking face to face for something you find hard to put into words. it also removes the 'oh....*shuffle shuffle*' if one were to get a polite refusal.
i like working from hard 'no's, it gives me more scope to be inventive and allow things to progress in their own way - the organic element of play for me. Conversely, a 'i'd really like to try such and such' or 'such and such is something i've been thinking about a lot' works well for me, particularly as there is an element of 'service top' in the way i play.
when i've played with someone more than once, then lists of 'to try' are sometimes good, so i can think about the next time we play together.
i also like to write, or be written to. A fantasy scenario is always a good starting point, from my perspective, particularly if the bottom enjoys role play. It tells me a lot of things they wouldn't necessarily say about themselves - they can project wants onto an 'unreal' situation.