26: Favourite Inspiration For Your Game
1: The players. Listen to their ideas, brainstorm with them, get other players and GMs in as well.
2: The game materials. If you’re here to play X, play X. Look back at what excited you about it, and your players as well. And look at what you don’t like and want to change too. (Not applicable to homebrew settings and systems, of course. There, take advantage of the blank slate.)
3: Appropriate media. Soak it up. Reread the books. Watch relevant and relevant-ish movies and TV - the dark alleys and criminal conspiracies in Person Of Interest have informed my current Vampire game a lot. Listen to mood music even if you don’t use it at the table. Search for websites and forums and art. Absorb it to the point you can take a plot from somewhere else and rework it for your setting as second nature.