I've got one on Tuesday that looks like my best shot at a new job since I got laid off in the summer. It's with a vice president of the company and the person whose position I'm filling since she got promoted
I'm just a little weirdo, I don't know how to make them want to hire me 
Look up interview questions for your position and write your answer down and recite them. Memorize them as much as possible.
Think of any interpersonal questions and memorize the answers for those too.
Think of any random question and remember the answers to those. Even if you don’t remember everything during the interview, you’ll be used to the QA environment and can be less rigid.
Do not drone for 5 minutes when they ask. Just a breather every now and then and be casual.
IME, interviewers tend to like being involved in your answer for whatever reason. Throw in a few “you know what I mean?” or “have you used [x product that’s tangentially related to the company/position]? Well I’m currently using it for my project…” or “do you remember if it’s x that does it or is it y?”