Everyone has made points worth following. I would however add one thing more.

If you insist on being or possessing something obscure, do not consistently refer to it. Lords, I cannot count the amount of posts I have read where RPers repeat and repeat their "mystical blue" eyes or their "mysterious expression". Please, we are all individuals here who are self-absorbed in our own amazing personages, we could care less about your amazing qualities and repetitive writing-style.

If you must be special physically, I simply beg you not to cram it down everyone's throats - if others choose to notice the first time, bully for them; if not, take a hint.