I'm not an actor, (P.S. If you're a girl, you're an ACTRESS) but I do know a little about casting. Honestly, it depends on the role. Some roles call for completely average people, others call for extremely gorgeous people. Some roles call for skinny people, others want slightly overweight people. Some roles want specific facial features, race, или abilities. It all depends on the role, the character, what the capricious casting people want, and, not to mention, how well Ты can act.