This morning I came across this Dan Chaon quote, which I read a few years ago and have always remembered for its comparison of writing short stories to novels (the former, says Chaon, is like going into a dark room, whereas the latter is like going into a dark gymnasium):
"To be perfectly honest, I found the transition into novel writing extremely hard. I was under contract with Ballantine to deliver a novel after Among the Missing, and I'd written a one-page proposal/summary, but I really had no idea how to proceed. As a short-story writer, I usually just start at the beginning and write through to the end. At first that's what I thought a novel would be like. I think that the way that I write stories is by instinct. You have some basic ideas — a character, or an image, or a situation that sounds compelling — and then you just feel your way around until you find the edges of your story. It's like going into a dark room… you stumble around until you find the walls and then inch your way to the light switch. With a novel, it's more like you're in a dark gymnasium, or a dark field. You can't stumble around blindly as easily and find your way."
I'm currently in that dark gymnasium, trying to find my way.