I'll post what I did recently on a similiar subject. I don't care what you look like, what you wear, or what you believe as long as you don't smell!

In all seriousness. The students I have trouble with come in two types. The first is not happy with the fact that some 25 year old "kid" (who looks like he is 15) is teaching them to fly. The second, due to success in other fields (such as their profession) thinks that they can apply this and they are automatically a good pilot. The last one is the worst, and in my view the most dangerous. The first type usually comes around after a few flights or just moves to another instructor.

Be yourself, be attentive, study, and come to lessons with questions and you shouldn't have any problems.