Start with a notebook, not another adjustment.
A maintenance log gives each change a little context. When something starts clicking, shifting poorly or feeling different, it helps to know what happened just before it.
Read the workshop note
Record the date, approximate distance, conditions and the symptom before reaching for a tool. A noise heard only when pedalling out of the saddle is a different observation from a noise heard while coasting. Describe what you can reproduce without declaring a cause too early.
Photograph the original arrangement before taking anything apart. Keep removed parts and small hardware organised. For each adjustment, note what changed and how you checked the result. Change one variable at a time where possible; otherwise a successful fix can be difficult to explain or repeat.
Use the service instructions for the exact component, including specified tools, lubricants and torque. A value from a similar-looking part is not a substitute. If the work involves steering, brakes or structural damage and you cannot verify it, have a qualified mechanic check the bike before riding.
A useful entry
Observation: what happened, and under what conditions?
Work: what was inspected, replaced or adjusted?
Reference: which component manual was used?
Result: what changed on inspection and a controlled test?
Follow-up: what still needs attention?
The goal is a record that your future self can understand, rather than a perfect spreadsheet.