Preparing yourself for the interview will help with the anxiety as you will feel more confident before going into your interview. Also, the more interviews you go through, you will get better at them as they are for the most part all similar. Another trick that sort of helped me get over my fears of interviewing was to quit putting so much importance on the interview or job for that matter. If I get it I get it, if not I'll keep looking. At least that's the attitude I adopted which did help me with interviewing.