I have a terrible memory so note-taking is really important for me. My notes have levelled up significantly since I started using a lightweight Bullet Journal-esque system but they still have plenty of room for improvement. Baldur Bjarnason’s “The different kinds of notes” is an interesting dive into various styles and techniques, with a bunch of interesting references and pointers.
Standards and conventions are great, especially when someone else has gone to the work of producing and documenting them so I can just adopt them. Conventional Comments is a neat standard for review/feedback comments (e.g. for GitHub PRs) - see also Conventional Commits for commit messages.