Interviews are difficult because we never know what to expect. Some employers will go out of their way to make you feel as comfortable as possible and will ask low key questions that seem easy to answer. Others believe in magnifying the stress of an already pressure-laden situation because they want to see how you handle it. In either case, if you can detach yourself from your nervousness, try to see if there is a pattern emerging. Do many of the questions concern attendance and reliability? Help yourself by emphasizing your track record in those areas. If the interviewer repeatedly asks about teamwork and any prior conflicts with co-workers, you can see what is considered important in this position -- sell yourself to it. If the primary concern is multi-tasking, focus on your ability to do many things at once -- work, family, volunteering, school, a history of working two jobs -- and how you are able to organize multiple demands to stay on top of many activities at once.
The key is to increase the chances of a successful interview by catering to the needs of the interviewer, not reciting a stale litany of overly-rehearsed responses.
More tips: http://www.unemploymentblues.com