Writing for me happens like plants grow, like songs bloom. I need a seed at the center, a hook into the melody line of the story. The kernel of the process can be a freeze-frame photo of the way someone's face looks, a line in someone's voice, an abrupt idea about the way someone's likely to react or likely to think or likely to want or know or feel. Then I write in whatever order the story comes out, and fill in around it where needed.