I'm kinda a weird one. I learnt English up to 9th grade and stopped because it bored me. Since then all I do is reading, a lot of reading. At first it was only manga and game, after that I tried out some visual novels and found that it was not that hard. In college, I only took 1 TOEIC test without any preparation (my friend and I played game upto 2am the day before the test, slept, continued to play upto noon and was almost late for the TOEIC test

) and it was enough for graduation, so I didn't have to take any English lesson in college also. Then I started reading English fantasy books like Lord of the Ring (Vietnamese translation is shit lmao), Witcher, Malazan,... But sadly I could not find anyone with the same flavour in books like me here, so I started using reddit and making alot of discussion there.
Anyway my point is that English overall is just a language,so I think the best way to improve it is to use it for what it is - a tool for comunication. It was also my thought in my first post here.