It was fascinating stuff but what it didn’t do was address some really basic questions about how to do an on-camera interview.

In the course of a long career at the BBC and as an independent producer I’ve interviewed hundreds of people including a Prime Minister (Blair), a reformed terrorist (Martin McGuinness), children who’ve been blinded by rubber bullets, Chinese doctors, bereaved mothers, captains of industry and of submarines, and many more – and I’ve tried to stick to a set of basic rules.

1. Ask open questions. A closed question is one that can be answered Yes or No – not much use when you get to the cutting room. So Tell me about your holiday is better than Did you have a good holiday (especially to a 1950s Prime Minister).

2. Listen to the answer. It never fails to amaze me how many TV interviewers simply run down their list of pre-prepared questions and never pick up on the interviewees’ answers. So they lose the chance to ask a supplementary question – an absolutely crucial element of any interview.

So the answer: The holiday was dreadful – a bear ate my wife shouldn’t be followed by And where will you go next year? Try something like What on earth happened? if you want to keep your job.

3. Don’t jump in. Unless you’re Paxman trying to stem a politician’s blather, it’s best to let the interviewee complete their answer even if it takes too long. Interrupting can throw them and make them feel insecure. And at the end of the answer, leave a pause before jumping in with the next question – sometimes the best part of an answer comes as an afterthought.

4. Look them in the eye. It’s crucial to develop a direct relationship with the interviewee. They’ll be distracted by the camera and crew and the best way to help them forget all that is to lock them into you by keeping direct eye contact all the time.

The truth is it’s really all common sense – and all part of being a good listener. So if you apply those rules the next time you’re chatting to the person next to you at a dinner party, you – and they -will have a more interesting time.

When I’m filming the interviews it’s often helpful for the client to have their family albums to hand, or on their laps, to trigger memories and stories.

And in the editing process we can use scores of such photos to create music sequences and turn the project into an engaging film.

But that assumes the photos are available – and quite often we have to press the client hard to dig them out.

People will often have a few framed photos on display – but I need much more, and that can involve the client digging around in bottom drawers, old suitcases and even the attic.

But the good news is that clients often don’t realise what they’ve got – so unearthing ancient photos of Granny that haven’t seen the light of day for a generation not only helps me and the film, but gives the client another opportunity to enhance the sideboard.

The best example was a client who I nagged endlessly to dig out what she had – whereupon she discovered that her son had a treasure trove of old family films from the 1930s of her parents in Hong Kong – which she’d never seen before. So I showed the films to her and filmed her reactions. Magic moments.