Here they are in no particular order:
i) recognise when you're too tired to write. Often I'd know because suddenly I found I was writing nonsense. The next day I'd turn on the computer, and the last sentence would be about my children, or about characters that weren't in this particular storyline. The sentence would have no bearing whatsoever on what I was writing.
ii) deadlines are the best motivators ever. There's no way I would've ever thought I could write 15,000 words in two days. My best ever total before was about 4650 in a day. Now I know I can do more -- I can ask more of myself.
iii) when on a big deadline, don't take time off in the middle -- or you might find you have to write 15,000 words in two days! (There's something about the aftermath of a writing retreat...)
iv) when trying to write lots, don't try to do it all in one session. Seems obvious, right? But it was something I'd never thought consciously about before. My 4650 (or thereabouts) was one sitting. That was how I did it. Now I'll think more about blocking out my day to include more than one session.
v) you don't have to follow your own process. I usually read over and edit the previous day's work, and this is how I started NaNo, but by the end I didn't feel I had the time to do this, booted up the computer and read over the last para or so, just to pick up where I was (and to delete that totally irrelevant sentence).
vi) you can work on more than one project at a time. At least I can. I never thought I could. A novel is such a big project that I love to immerse myself in it. Think of it and nothing else. For months on end. No short stories when I'm novelling. This month though, I did a scene of the group novel we're writing for writers' group (contemporary novel cf to fantasy NaNo) and a chapter and a half of my other novel. My NaNo novel was book 2, so I was in the same world with some of the same characters, but still a different headspace.
vii) make hay while the sun shines and all of that. I could've got ahead on NaNo in the early days when I was at the island, but instead I worked on my first novel. Still, being under pressure at the end and letting the writing consume my days meant I got more done.
viii) I really don't like writing on my laptop. The motor vibrates under my left wrist, and very quickly my wrist starts to itch and burn (not literally burn). This time I stuck teatowels between my wrist and the laptop, but could still feel it. Give me my desktop and WordPerfect any time.
I'm sure there's more so I may do a follow-up post later, depending of whether I can think of anything else.