Maintain good posture. Bring extra copies of your resume and, if appropriate, a portfolio or samples of your work. Bring letters of recommendation or have them sent prior to the interview, if requested. You may want to carry a note pad in a portfolio. Your resumes, list of references and paper should all be in one place.
Many interviewers make a judgment within the first four minutes.
Try to project qualities such as enthusiasm, interest, flexibility and willingness to work. Be aware that the receptionist and other staff may be as important to impress as the interviewer. Shake hands before and after the meeting. Remember the interviewer's name and use it. Some initial anxiety is expected and acceptable, and sends the message that this is an important event to you.