In case you thought it gets any easier, it doesn't, not even after you write 30 books, or so experienced authors say in this lovely encouraging article from Huffington Post:
What Has Surprised You About The Writing Life?
Lisa Gardner: What surprises me is that it doesn't get easier. With thirty books written, you would think I'd feel proficient, but each book is painful in its own way. I'm always just feeling my way to that other side—the completed novel. I feel I'm forever gnashing my teeth and banging my head against a blank computer screen.
Faye Kellerman: The biggest surprise is that it doesn't get easier. With most tasks, the more you perform them, the more rote they become. With writing, you can never, ever, sit back and have it come easily. It's a joy, but it's a struggle. It always gives me a headache. The more you write, the harder it gets because you've used up plots; you've used up characters; you've used up words.
Ian Rankin: What's surprised me is that as I get older, writing doesn't get easier. When I started, I thought this would be like being a car mechanic. Once you've stripped enough engines and put them back together, you can do it blindfolded. But for a writer, each book is different. It's never the same engine. You want to make this one the book. We keep going because none of us has written the perfect book--the distillation of everything you want to say about the world.
Well then, back to the writing desk we go.