How to succeed in an interview
When we have tasks, we can feel overwhelmed, and I use the metaphor of cutting down a tree to describe this. At first, the whole tree seems overwhelming, but as you begin to cut it down, you feel differently. You do not begin to feel differently when the tree is cut down, but as soon as you start to cut it. Therefore, just do the next right thing, work within compartments of an hour by hour basis. It is the anticipation of an event that gives us fear that is worse than the event itself. Perhaps during, but definitely, after your interview, I promise you that you will feel better.
Preparation is important, and being calm and going to the interview feeling relaxed (as much as is possible) is important. Have the clothes on that you feel good in, and get to the interview with plenty of time to spare; this is really important. Also, aim to sleep as well as you can the night before the interview.
Everyone is in the same boat as you. All the other people who are being interviewed are nervous too. They want to see someone good! You are good. Sometimes, I have been too arrogant in these situations and thought that I am too good for the position because I feared secretly that I wasn’t good enough. They are good and you are good! There is nothing to hide - you can enjoy this, honest! It is a chance to show people what you would like to do if you worked/studied with them. If they asked you for an interview they already like you.
At the end of the interview, say "I want to re-state my interest in working here/being a student at this University. Thank you". However, only say this if you mean it. Remember you are interviewing them too; they want a good employee and/or student also. Remember there is nothing more similar to us, which we can relate to more, than another human being. They are all human! If you have a panel interview, this may perhaps be the hardest part of the day; but not necessarily!
I have had panel interviews before and I was a little nervous, but everyone else who was interviewed would have been nervous too, and the panel is expecting that. I did get the job. However, as long as you are yourself and comfortable, then if the job or place is meant to be yours, it will be. If not, it won’t. Sometimes, courses and jobs don’t suit us, and it is as important to know what we don’t want as much as knowing what we do.
If you just do your best, you can’t do any more than that. You may feel nervous, but that is OK! Please don’t beat yourself up for beating yourself up; mental double-edged clubs are no good. If you feel bad and nervous that is ok; accept it (then it usually lessens). Just think about how good you will feel after the interview is done. Just be yourself, that is always enough, no matter what you are doing in your life and if we make mistakes, they are great, as they teach us something about the next time we are in the same situation.