I think when yo have to do an interview job you have to satisfy a group of qualities. It is very important the first impresion. Before to go you must think what is the interview that yoou have, becasue sometimes you must dress more elegant thant the other case . It's very important to look natural and very confidence. The qualifications and experience depending the job it isn't de most important. Some manager could think if you have been working for a long time in another company you could have bad habits, or if you jave high qualifications perhaps you are a person most difficult to convince.
The personality is one of the most important thing, you must show them very sure and a person than want to learn and to work a lot and a person who knows to explain his ideas clearly