I think the main thing to keep in mind for any job interview is to really showcase your personality and to be confident.
To get as far as the interview stage, potential employers have studied your CV and covering letter, and already decided that you probably have the right credentials and experience for the job. So although the interview feels like a grilling, and that your answers are being scrutinised, it's actually more an opportunity to get to know you, and assess if you are a good fit for the organisation.
So the objective is to be calm, friendly, and give considered answers that demonstrates your strengths, without getting too bogged down with the content.
This is particularly important if you are going for a management position, where being able to communicate effectively and remaining calm under pressure are of vital importance.