An interview can be seen as a dreaded ordeal or a welcome opportunity to learn more about a potential position, to highlight your strengths and to assist the employer in determining what a great match you would be for the job. Your attitude will be governed largely by the preparation you do in advance of the interview.
Interviews are a little like oral exams.
Preparation is the key. Rarely will personality or charisma alone carry the day. Know what your strengths are and what you want the recruiter to leave the interview knowing about you. Answering a question in your head and how it comes out of your mouth are two completely different things. Make sure you practice with other people talking to yourself isn't enough.