I think the most importat quality for a job interview is your appereance, sometimes when a company wants to have an interview with you is because they like your qualifications and your work experience (you have sent a CV before). So, in an interview is so important your appereance: you must be as natural as you can, and show your personality accordance wiht the other qualities.
Some years ago I have been interviewed for a job (my last job). It was interesting because I have met the boss I have now and the manager too. They talk about my future job, about the company, they asked me a lot of questions about my experience, but not about my qualifications. At the end I have won a perfect place in the company.
Try to find a company you would work to. Send a complete CV, with all the most important information about you you want to give to the company.
Lidia