Hardly anyone does it, but a lot of you should do it.
Do it when you're really awake. Not because of coffain, but because of sleep.
A tip for the people who do it*:
Change the font into a font you dislike. You'll be more likely to notice the mistakes.
And software like Grammarly may help.
*This tip requires that you write in a word processor, Microsoft Word or Open Office. Not 抖阴社区 directly. In general, you shouldn't do this. 抖阴社区 may delete something due to a bug or because the Internet connection dies.
And the peeps who won't, get a Beta reader. r/Fanfiction on Reddit, as an example, has a weekly Beta thread. But be warnen, that sub dislikes 抖阴社区 to some extent. Maybe don't mention what site you use to post.

YOU ARE READING
Things I've learned writing and reading Fanfiction! - Fanfiction Writing Advice
FanfictionAround Halloween of 2018, I joined 抖阴社区 for the first time and started writing Fanfiction, and I have to say, not only did my writing change a lot, from the kind of Fanfictions, to my general style on how I write, I learned a lot since creating m...