Even casual consumers of SF recognize this definition—penned by our namesake James Gunn—on the most basic level: that futuristic technology requires invention; that a Jekyll becoming a Hyde entails transformation; that artificial intelligence achieving sentience sparks revolution. We cannot write SF without change. The great storytellers in the genre embrace this and delve even deeper, turning the notion of change into a question: Why?
First draft: In your first draft you get to be Wild Being of the Woods. Write crazy. Stop and start, veer off, break rules, color outside the lines. Let the story discover itself. Later you can figure out what to do with it.