I used to get really nervous during interviews. What I've learned to do is start asking questions first--Can I ask you a question? How did you get started here? Why did you choose this company? etc.. This usually allows me to get to know the person I'm talking to and I usually have something similar/relatable to talk about when it comes to me answering their questions. Remember that an interview doesn't have to be completely one sided (that would be an interrogation!).
