I don't create OCs - I (only) create alternate versions of myself in different universes. (Because I actually believe that there are different universes and that everyone has a counterpart in the other universe - like in [the original] FMA.)
And I have a lot of fun doing this.
Like, let's say, for example, that in this other world the inhabitants have different heights than in our world - then the version of myself in that world probably would not have the same height as I do in RL.
But instead of just choosing a randmon number - like you would do for a normal OC - I would look up all the heights known in that world, then I'd do research on heights in the real world, compare it to my height and calculate how tall I would be in this other world.
And that is super fun!
The only "real" OC that I have is a Hetalia OC, because there I could also a lot of research - sorry, I mean, A LOT of research.
Yep, I think that's fun!