Aside from recycling characters (which I'm aware I do a lot
), I also tend to gravitate towards the same list of character names for minor characters, the occasional OFC in a oneshot, and characters that other characters just reference.
For example, one name that tends to be one I go to for character references is "Allie." If there's a sister referenced in a story, her name tends to be either Olivia or Chloe for some reason. I've never had actual, full-fledged characters with any of these names, but the names are referenced a lot.