Given that I've brain-imagined up a big cast of privates-pleasing characters now, I figured I'd make some pools for the ones that show up repeatedly (to their misfortune, or their pleasure, or both). In some cases there are also OCs from other lovely people that I've taken a liking to.
Sometimes certain characters show up in random stories. So, this way, if you want to find stories featuring a certain character, you'll be able to find all the content containing them in one place.
I haven't done it for every character. But all the main/recurring ones are represented.