Flying By the Seat!...
If I had to have the full path of a story in my head and an outline written, I'd never write anything beyond songs and Prose entries. My brain just doesn't work that way, putting it all together first. No, I generally get an idea first. Like, I may be on the bus and then a passenger causes me to think, "You know what would be a great idea for a story? A book about a bus passenger going ballistic and killing everyone on the bus." Then I'll have the title in about 3-4 mins, and shortly after that, maybe the main character's name, gender, description, and perhaps even a scene or two that I want to make sure to have. All of this gets written down in a notebad app on my phone. By the time I actually sit down to write, I've figured out the first scene, but little else. I just kind of wing it from the first word onward.