One cliché that I really cant take anymore is the "parent was killed by X, so therefore does OC hate race X". Yes its nice that your char hates griffins, dragons, changelings or what not, but please give me another reason than the death of a parent.
The whole "was left alone and had to defend for him/herself, and are now the strongest in the world" trope is also really overdone if you ask me. Sure a character becomes gritty if you do something like that, but I do not want grint in my else lovely smooth RP, thank you were much.