I always try to make a version of myself, or if it is a fantasy thing(like my WoW troll), I try to make them as close to my human form as possible, and if their is something that cant be copied, make it best suited for the class I want to do. I ended up making my troll have tall red hair that looked like fire because I was a fire mage. The best realistic one I have made so far is my Mass Effect character, but it was too limited, plus I had to make myself look his age instead of a teenager. No glasses or semi-afro hairstyle either.