Fleshed-out world cheat sheet:
Pick your favorite book/movie fantasy world, and rename the major entities. That way, you can quickly draw from what you already know and have answers for those tedious PC questions like, "so, what's across the river?" or "what do the people in this town do?"
Side note: at least 50% of my world-fleshing ideas go unnoticed. But at least they're there.
Side side note: "Fleshing out?" Did a necromancer make that term up?