Reading the docs and searching into it on a regular basis is the single best advice I could give to Vim users wanting to improve. The odd cheatsheet, the post with a few tricks and cool plugins, all those can be well and good, but nothing beats sitting down and reading the docs. I've been use Vim daily for 10+ years, and I still check help files very regularly. Knowing _how_ to search efficiently is also a skill worth acquiring.

Incidentally, the same advice apply to Bash: just read the man page, and search into it each time it is needed. It is just worth it.