Think of the game you want to run; the emotions you wanna evoke, the pacing, the mood, the tone. Now make a small list of themes--maybe in the form of key words or maybe just images you could stick to a virtual image board or copy/paste into a word document (I often have the names of movies, characters from fiction, scenes from specific movies, or sometimes just clever ads or album covers). Maybe even prepare a short plain statement describing how you would want your players to describe your game, elevator pitch style.

Now, whenever you run into a snag in the game--something that...