nikhilpareek1333 minutes ago for me its writing WHY in commit messages and PR descriptions, not just WHAT. I started doing this seriously about three years ago after I wasted half a day trying to figure out why a piece of code did something weird, only to realise past-me had written it and didn't leave a not. Now every non-obvious change I make gets a short paragraph of context. I constantly hit "wait, why did we do it this way" moments in my own code, and git blame either has the answer or it doesn't.
A similar vein, asking why in PRs. Most people don’t do the above, and asking why when it doesn’t make sense really helps understanding what your colleagues are actually thinking. Helps create a unified perspective on the codebase.