BenC

Don't worry so much about what you wear to class; it will certainly be different from what you wear teaching. Most of the grad students I know, which includes TA's I've had class with, dressed in whatever way they felt comfortable. Sometimes that was very casual, and sometimes not. Most of the time though, they looked like the rest of the students in the lecture/class when they were not teaching. Just find your own grove and style, don't change completely to fit in.