Research the position and know what is expected of the position for this particular organization. What are the responsibilities, the qualifications required, and the special projects? Once you know these, demonstrate your abilities to meet the requirements and special duties of the position based on your past experience in similar positions or your education.
I once interviewed a candidate for a position called Laboratory Supervisor. When the candidate was asked about his supervisory experience, he said he didn’t know the position we were interviewing for was a supervisory position. I did not listen to anything he said after that, and neither did any of the other panel members. When applying for manager and supervisory positions, provide examples of how you have done this in the past, or demonstrate that you know what you need to do if you become a supervisor. For any position, you need to know what it entails so you can provide example about your background to prove you can handle the responsibilities.