I have always wanted to write a stage play. However, what I'd like to write is intensely personal, and I'm not ready to say the things that would need to be said. It would emerge sounding stilted and stupid, as though I were avoiding saying certain things. Which is, in fact, what I would be doing if I tried to write it now. It involves my childhood, and it would be hard to write. So I'm putting it off for the time being.
So instead I got started taking a look at how to write a screenplay. I've come up with a basic concept, which I was quite pleased to be able to do, since I've never done this before, and one doesn't know, when you try something new, whether or not you'll be able to accomplish even that much. I bought a bunch of books, and one of the things I've noticed as I read them is that they inform my novel-writing abilities more and more. The thing that's interesting about screenplays (from my perspective) is how visual the story must be, if it's going to be effective.
Now, if you're writing a literary novel, you have all sorts of room for interior monologue, and you can take a page to describe what a room looks like, what fabrics feel like, the color of a boy's skin or the smell of the fireplace. In a screenplay, all of that must be conveyed immediately, and it must be conveyed through the medium of the eyes. There is no room whatsoever for embellishment. Dialogue becomes the device that moves the plot even more so than in a novel. All of this has taught me to look at my characters and my scenes very differently, and I think it's been enormously helpful to my fiction writing, because every time I crack open a screenplay-writing guidebook, I get new inspiration about how to see my characters more clearly.