Different every time. You can make generalizations about writing all day long. A lot of them are true. But what makes writing so fascinating and frustrating is the specificity of each story and the new problems each story presents.
Not to say you don’t learn. You do. You learn many things that will help you as you write—if you’re paying attention. You get help from teachers and other writers and wherever you can get it and you learn from reading etc.. —if you’re paying attention. But once you’re into a new story, no matter what you’ve learned, you have new situations that make the telling a struggle, a new struggle—every time. And you know what? I’m glad. Oh, don’t get me wrong. I think I’d like to have it all figured out and just sit down and effortlessly write my new novel and after a few months write THE END at the bottom. Maybe I’d revise a few words here and there and try to work in "verisimilitude" since I seldom get to use that word. Off it would go. PERFECT, my agent would say. PERFECT, my editor would say. I think that I would love this "fiction" sometimes, this ease, (particularly when I’m hitting that wall again and again which happens in every manuscript sooner or later) but it’s not true. What makes writing worthy of a life-long pursuit is that it cannot be tamed. All but the most simple, formula-driven, fiction will force the writer, no matter how experienced he or she thinks he or she is, into unfamiliar worlds. It will challenge them in ways they can’t anticipate. That’s what makes it, in an admittedly twisted way, fun.