Corporate websites and YouTube is full of Interviews with experts providing their opinion or views on a topical subject. It could be a quick 1-minute chat at an event or a proper sit down interview.
Work on which questions to ask in advance, make them open and specific to the topic. With generic questions and closed questions the audience will quickly switch off, try and be specific.
Try and remove shadows, expensive lighting equipment may not be available so use desktop lamps at different angles and intensity. Strong lighting from above creates shadows on the face so switch them off and use lighting from various sides.
Probably the most important aspect of a video. Without sound you have nothing, an excellent sound will help a great deal keep the audience listening. If you are going to do these interviews on a regular basis then splash out on a microphone, one of those tie mics are not too expensive and will make your video a million dollars’ worth.
Try and keep the interviewer out of the shot, film it a little from the side and get the interviewee to talk to someone and not at the camera, it makes it more natural and less staged.
If you can film it with 2 cameras editing will be fun as you break up the interview with different angles. You will find this much easier on the eye. Keep a keen eye on reflections too, you don't want to see the camera in the back ground.
With a tie mic this can be reduced, so watch out for air-conditioning vents, mobile phone interference and people walking and talking in earshot.
Good luck with your next video!