Framing your face with your hair carefully is probably good. And yeah, not being 100% looking towards the camera sounds good.
If really, your chin bothers you, you could have the picture taken with it partly buried in a scarf.
I don't know if it's the case, but I think if you lose your card, they take a new photo. So if it's awful, it's not hopeless. If I'm right, that is.