That's very impressive that you managed to write that much in that amount of time. Definitely a skill.
Well, my technique involves a lot of avoidance. I avoid playing and getting engrossed in games (online and offline), watching movies, animes, or any other shows (except documentaries about the topics I'm researching), reading manga, novels, or light novels, and going outside when I'm on my 'writing mode'. In fact, my teammates would often complain about me missing on game events before, until they got used to my work style.
Also, I do some planning and research on the theme I'm writing about before actually penning it. I always start a volume writing on notebooks, before eventually moving to digital once I got my 'writing mode' on. Once I finished the book, I'd stop for at least a month, before picking up on where I left off.
That way, I could write up to 10k-12k per day (once I'm on a roll), and 2k-6k whenever I'm trying to get myself on the mood (just like how we warm up a car before driving). But yeah, sites like WebNovel would kill me, since I'd stop for a month or two before writing the next volumes. (They require a daily quota of 1k words per day, minimum.)
I'm doing this just for a hobby, though some may wonder about my efforts being way too 'professional'. I'd say
"nah, I just want to finish something that I already started."
