I got rid of my glasses and they changed my hair. That's really all they did. They went shopping for me, so the clothes are different too. It wasn't like Extreme Makeover where I got a nose job or anything.
You can relax more when you're playing a silly character than when you're playing a really rigid character. But to be fair, I think George Clooney is a bigger teenager than any of the 'Twilight' cast. He's the guy throwing a football at your head and then hiding around the corner, pretending it wasn

