When I need to further imagineer a situation that comes up in play, or get a mental handle on what the situation is, my main technique is:
A) What would happen in a Jack Vance story? When I need to know the character of a village, or the schemes of the NPCs, or any other sort of improvisational jazz, 99% of the time I pretend it's a Jack Vance story and go with what comes to mind. Usually this results in lots of NPC jerks in the campaign, which I think keeps things spicy.
B) However, when dealing with the Weird, the Preternatural, "The Mythic Underworld" and the lands of "Tyranny and Mutation," 99% of the time I think of how things would be in a Clark Ashton Smith story and go with that for how the situation develops. This does not discount Vancian Magic-Users by any means!