Choose labels you can hold in your head
A tag list is a working-memory object, so it obeys working-memory limits.
Keep 10-12 labels. That is not tidiness for its own sake: beyond a dozen flat labels, choosing one takes longer than the highlight is worth, and the session starts producing pairs like 'memory' and 'memorisation' that split your search results between them.
Write labels as single lowercase words, one idea each. When a highlight seems to need a new label, type the first three letters into the tag field and read what autocomplete offers; if an existing label covers the highlight, use it and move on.
Reserve new-label creation for the monthly audit, when you can see the whole list at once. Merging two near-duplicates then is a one-minute job; discovering them across six months of exports is an afternoon.
- One word, lowercase, no punctuation
- No two labels with the same meaning or stem
- New labels are created only at the monthly audit, never mid-session
- When in doubt, reuse: a slightly wrong existing label beats a perfect new duplicate