A small reference notebook
Leave notes that another session can use
Record observations plainly
A short note should say what was observed, when it was observed and what remains unknown. Separate a direct observation from an explanation that has not been tested. That distinction lets a later reader use the evidence without inheriting every assumption.
Keep private material private
A shared note rarely needs an account password or a complete private log. A description of the error category and a controlled reference can preserve the useful context. Store the original only where the responsible person can manage its access.
End at the agreed result
Useful notes make the next necessary step visible. They do not need to turn every possible improvement into unfinished work. State what is complete, identify any result that still needs confirmation, and keep unrelated ideas out of the handoff.