Tell the interviewer about business situations where you successfully used a skill and elaborate on the outcome. Don't be afraid to admit mistakes. Employers want to know what mistakes you have made and and how you have learned from them. Don't be afraid to admit making mistakes in the past, but continuously stress your positive qualities as well, and how you have turned negatives into positive results. Relate stories or examples that heighten your past experience.
Past performance is the best indicator of future performance.
If you were successful at one company, odds are you can succeed at another. Be ready to sell your skills and performance in the interview. Know everything about your potential employer before the interview. Customize your answers as much as possible in terms of the needs of the employer. This requires that you complete research, before the interview, about the company, its customers, and the work you anticipate doing.