My characters tend to be buff, have traits such as claws and pointed teeth (if the character's species or other things like being a werewolf allows that), and have longer hair, sometimes it's a bright color, a kinda pronounced cheekbones, larger noses, and often have bright almost glowing eye colors, and almost always have scars.
Rowan (Skyrim OC): buff, bright long hair, smaller scars, claws
SHyren (Skyrim OC, werewolf form): werewolf, giant scar on the face, monster traits, long hair
Ortheka (WoW OC): scar, monster traits, fluffy hair, cheekbones
V (my DC Comics OC): probably one of the few who don't have scars, buff, big fluffy hair, glowing eyes, monster traits (claws, teeth, they're not shown)