"do not add tags, create projects, or create other to-do infrastructure..."

This sounds like you aren't a fan of the Allen 'GTD' process, which has a lot of that infrastructure. If you've tried but discarded it, that would be a good read.

I've sort-of used it for years, but lately been finding it creates a lot of busywork that masquerades as accomplishment, but not sure what would work better. (I felt it worked better in the past, not sure when things went off-track.)