Entering in the room
Enter in the room with due permission of the interviewer. Shake hands firmly and wish the interviewer as per time of day. Radiate your confidence with smile. Dress conservatively. Be always on time. Be a stickler for promptness while answering the questions with aplomb. Spontaneity is the buzzword. Remember the interviewer's name.
When the interviewer tells you to sit or gestures you to sit down then do so after thanking him. Look alert. Sit up erect. Maintain eye contact with the interviewer all the time. Speak with confidence and assurance. Interviewers like candidates who are not shaky but are enthusiastic and responsive.
Answer questions openly, spontaneously without holding back and beating around the bush. Yet be direct and to the point, avoiding long, drawn-out explanations.
Keep it Simple and Straight
If put on the defensive (e.g. "Why do you shift jobs so frequently?" Why are you changing now?") answer as simply and succinctly as possible. Keep smiling.
Don't dwell on carping and caviling at faults of previous or present employer.
Do not smoke or chew gum during interviews. It shows disrespect towards interviewer. Do not ask direct questions about salary or other benefits at the beginning of the interview. Do not slouch in the chair, tap your feet, play with eyeglasses, pencil, or fidget nervously.
Learn about the company
Do your homework and learn as much as you can about the company and the job requirement.
Start from the basics
Prepare and rehearse common questions and answers. For example - What was the nature of your job? What special skills did you acquire? Were any special goals set for you? What was your day like on your job? What were your strengths? Weaknesses? Why are you considering leaving your present job? Why are you interested in this company and how can you contribute?
If you have it, flaunt it
Stress on your achievements. For example: Processes developed, sales records achieved, systems installed, absenteeism reduced, product or production improved, etc.
Leave the door open
Never tell the interviewer that you are not interested in the job. Leave the door open. The first interview is not the place to turn down an offer. Do not tell about interviews you have had or plan to have.
Ask for the Job
If you are favorably impressed and know all the details of the position, then ask for the job.
Say thanks while concluding the interview
While concluding the interview, thank the interviewer for the time and consideration given to you. Ask when you should meet again to discuss the position further. It often takes several interviews to obtain the job offer. Ask for a business card and give yours in return.