In my games, I choose a theme on which I will base all the clues, and then I tie it to the players' profiles.
For example, musical instruments (a list of them is created, players choose any available from the list, and a hint is created for a specific instrument (there is plenty of information and facts in the wiki, and not only there (an example with the magic violin)).
But even just from the wiki, you can encrypt a lot of things.
And so it can be anything, actors, directors, generals, tarot decks, countries... in general, anything that has information.))
Added 1 minute ago
Okay, I always do that.