Most of the people attending interviews are generally tense fearing the worst in the big moments ahead. While their tension is understandable, there is no actual need for the same. How you prepare mentaly and for the tests of the interview are widely known. Here are a few other tips when you attend an interview.
Try to take at least 3 copies of your resume or CV to the interview. This way you can hand one to all the interviewers in the room and none of them has to stare at you. Not only will they feel comfortable with something in their hands to look at when you tell about yourself but you also make a statement about yourself without even opening your mouth.
Always carry a water bottle to the interview. You never know how long it will take for your turn and you don't want to be late when you are called on your turn. It will also water down your nervousness.
(AW- Anil)