Novels and plays are both full-length works and both challenging to write well. I've been writing plays for such a long time now that it seems second nature to me, and the process feels comfortable.
I'm only on my second novel, and man, sometimes I'm just stunned by how tough it is. There are just so many words. I did a check, and my recent full-length plays, even though they come in around 100 pages, run between 15,000 and 19,000 words. Not bad. But my current novel is sitting around 90,000 words, and that's after I cut 15,000 words from the first draft. That's an whole full-length plays's worth!
I can keep an entire full-length play in my head at once. When I'm working, I have a pretty good sense of everything that every character has said, and every scene, even every beat. I can run the whole thing through in my mind, in one sitting. I'm not sure I can say that of my novel. Getting the first draft down is fun as hell, because I don't worry too much about how it all fits together. I just plow ahead, and figure I'll sort it all out later.
Well, I'm in the sort it out later phase, and it's tricky. I try to be organized about it--I have a notebook where I keep in revision plans and strategies and notes. I'll do waves of purging bad habit words (I have lots). Then expansion. Character work. Descriptive work. Rhythm. Style . I have to say I now truly appreciate the great books that I read. I'd like to read a lot more from writers I admire about how they handle the revision process. If you know of any such books or articles, I'd love to hear suggestions.
The toughest part is just remembering that writing a novel is like running a marathon. I just need to keep showing up to my desk every day, make some progress, and as the months go by, it starts to add up.
(Coming soon: why writing plays is harder than writing novels.)