Prior to this year, I have had three formal interviews. Ones where I had a resume prepared and had to dress for the occasion. This small sample size has been a difficult hurdle, due to the fact that one of those interviews was for a company my father owned, another was for a call center that would take any human, and the third was for a resident assistant position. None of them really business related. Let me give you some advice, interviewing is as much doing your homework on the company as it is being qualified for the position.
Here are three pieces of advice:
1) Know why you want to work for company/firm/person/etc.
2) Find out what questions they will ask - then practice
3) Be authentic