You need to be researched, reasonable, rhetorical and fluent. An argument based on fact, presented strongly, is much better than an argument based on anger, which is blurted out.

Remember, even five minutes of research will make an interview better. If you only have ten minutes to get ready for an interview, and spend five of those minutes preparing, it will make it much better than if you had gone in cold.

You can plan your interview so that you think 'I'm interested in the following three answers', then it's not so much this question it's the one afterwards. If the person answers in a certain way you can change the next question you ask to ensure you cover the topic you want. So you can certainly plan your interview in advance.

Avoid argument that allows no consideration of the other side's point of view and that completely rules out anything good at all about the other side. It is no good simply attacking across the board.

Be aware that they want it to be over quickly so be efficient from the very beginning. Arrive early and prepare yourself and your crew so your subject isn't delayed. You should also find out something about your interviewee before you meet them so there is some chance for small talk. Reassure them everything is going to plan and ask them if they would like to know what the procedure will be. Finally, remember if you have a crew don't forget they have names - introduce them to your subject.

I used to interview Bill Gates quite often and in the early interviews it was very difficult as I tried to interrupt him to put the question to him that I had planned. As time went on I learnt he would take the difficult questions but he wanted it to be more of a dialogue and he wanted to feel he was there to cover all matters, including his opinions not just mine.

I was in New York on 9/11 and ended up interviewing people a few hours after the attacks, when they were walking through Times Square covered in dust. The simple thing to do there was to encourage them to tell their story. Don't ask someone how they feel in such a situation, try to think you are in that person's position and work out how you would feel. You need to work out what question would get you talking the most.

Speak in a language that comes most naturally to you and present your opinions in the same way you'd explain them to a friend. A strong point of view is always an interesting thing to listen to, but especially if it can show some warmth and humility. Make sure you can explain your point of view in a simple sentence to make sure you actually have a good argument. Remember a TV viewer can see through people who have nothing to offer.