I love that when you're writing your mind is sort of figuring things out on its own, without you directing it.
Ideas mostly come from the work itself. Often when I'm drawing, the words will be bouncing around in my head, and when I'm writing, ideas about the drawing happen.
I had read [Charles] Dickens's novels were often published serially. I thought it would be fun to write a book, just sitting down and writing a chapter every day, not knowing what would happen next. So that's how I wrote the first draft. And then of course I had to go back and make sure everything worked and change things.