Practice interviewing! Try and arrange at least one mock interview with a faculty member or your DCT. During my mock interview, I was surprised at how flustered and inarticulate I was, even when my DCT threw me an easy question (e.g., what is your dissertation about?). So I practiced a lot, by myself, using my cats as the interviewers, lol. I just practiced out loud the questions that I anticipated (e.g., why this site, describe a difficult case, what are your goals, what are you looking for in a supervisor), and it really helped. The interviewing will get easier as you move through interviews, but better to be prepared for those first couple by practicing beforehand.
Read this book –
http://www.amazon.com/Internships-Psychology-Workbook-Successful-Applications/dp/143381210X – (available as an ebook) that details out the internship process from beginning to end. I found it very helpful, particularly the sample questions – both questions you may be asked by interviewers, and sample questions you could ask interviewers/current interns at the interview.
Don't book two interviews on two consecutive days. It is good to have "padding" in between interviews, especially if you are traveling far in between two interviews. You never know what will come up, and you may need to reschedule your flight, so that extra day will really come in handy. Last year, there was that "polar vortex," and a LOT of my flights were running very late, or were canceled, but luckily, I had time in between interviews, and was able to make it to them all by rescheduling canceled flights, or arriving a little later than anticipated.
Don't check your luggage. It's a pain, and often times you will be running from one place to the next, and you will be thankful that you don't have to stop and check your luggage, and then wait for it after you arrive. Or your luggage could straight up get lost, and you could end up showing up to the interview in what you wore on the plane. If you absolutely must check your luggage, at least carry your suit on with you.
Try to schedule interviews geographically. This is not always possible, because it depends on when sites get back to you, but try to schedule your interviews by geographic region if you can. So, if you have three interviews in one week, it's much easier to bounce around from Arkansas to Mississippi to Kentucky, than to bounce from Chicago to Seattle to Florida or whatever.
Relax and be yourself. This sounds cliché and easier said than done, but once you get to the interview, remind yourself that you were selected to interview for a reason, the site wants to get to know you better. Let them get to know you.
🙂