I grew up on L. J Smith and Sailor Moon. Every single show I watched or book I read marked their supernatural beings with some super special physical marker. Be it unnatural beauty, purple eyes, or crescent moons on their foreheads. So naturally when I wrote my gods, I had to follow suite. So my gods are ridiculously attractive ala L. J Smith and my demigods have a very distinct look determined by the ichor in their blood.
There are more examples of this than I can detail (though do chime in with your favorite ones!) but I thought I’d share this extremely funny comic that toys with that trope.