For pics that don't fit neatly into an album theme I'll group them by date, "Family pics 1995-1996" based on their quantity.
Then I'll print photobooks, adding info where possible about location, date, and people. Basically, recreating physical photo albums. I'll print 2-5 copies of each album, depending if I expect to send copies to other family members or not.
Having physically-printed photos works both as a last-ditch backup and as easy access for anyone to browse. I nostalgically remember spending time as a kid flipping through my parent's and grandparent's photo albums - sometimes with them, but many times on my own. I want to ensure my own kids can have the same experience.