Writing Fiction in Four Easy Steps!

Teresa at Making Light has a a simple four-item formula for turning story into fiction:

1. Move and keep moving.
2. Make it consequential.
3. Recycle your characters.
4. See if you already have one.

Details here. Like anything complicated, this simplifies the matter entirely, but could serve as a good jumping off point. Plus, as a commenter notes, it's usually a good idea to know what the rules are - or to at least think about them! - before deciding to break them.