How do you prepare to run a game for the first time?

There's that moment when you've read a game you haven't played before: the moment you decide you're actually going to run it.

What sort of techniques do you use?
 
My process is to try and build up a mental picture of what a play session would be like, and what information I'd need in order to run it well. I do that by:

• asking questions
• identifying gaps in my understanding
• clarifying the designer's intentions--through my own reading of the game, if possible
• looking for reference sheets I can use while I'm playing / running

It ends up being a bit like a reader's commentary.

This is something I think I'm going to be doing regularly here. I'll use the hashtag/label: #gameprep

Here are some examples:

I've just analysed Wield by John Wick and Gillian Fraser, which looks like a great game and got rave reviews at Kapcon this year.

Here's the second half of one for Circle of Hands by Ron Edwards.

I'll make an initial post here, and then put my follow-up comments on Google Plus as I read and ask questions. I think that's the best way to keep all of my observations in one play, that's still searchable later on.
That may or may not be followed up with an actual review of the game.