One thing I'm noticing when people make assholes is that they tack something like "has a sensitive side" or "Is really a nice guy" at the end of their personality section. But, never showing it in their IC-posts. 

I'm guilty of this myself, but there are other, more organic, ways of showing your character isn't a total cunt, or just writing down their dickish aspects like they really want to so people will like their character.