Dress like you normally do, formal outfit with a Tie is always recommended. DO NOT wear loud outfit.
Try reaching the place a few minutes early than one minute late. Interviewers have a busy schedule and if you are late, it will cut down the amount of time allotted to you.
The very first question any interviewer asks is Tell us something about yourself?. Prepare yourself for this question. Your education, family background, experience and so on.
Always know what your strengths and weaknesses are ?
Be honest, about yourself. Adapting to the interviewer’s moods and emotions is as important as recognizing your own. Effective listening and observation is required from your side.
It is important for you to find out as much as you can about the organization, agency, institution, and so on, with which you are interviewing.
The best way to improve your communication skills is to practice role-playing before the interview. Consider participating in a mock interview through a friend, your spouse, or roommate, to help simulate an interview or practice in front of a mirror.