How We Met: Jonathan Miller & Isabella Bywater

'It's rather like rugger – if you make a pass and they can catch it and run, you score a try'

Isabella Bywater is a set and costume designer for opera and theatre. She has designed more than 50 productions in collaboration with directors including Deborah Warner, Nicholas Hytner and Stephen Medcalf. She lives in Kilburn, west London, with her husband and daughter

I first saw Jonathan when I was at college and he was directing The Turn of the Screw at the English National Opera (ENO) [in 1979]. Somebody pointed him out in the canteen; it was very exciting, as he was a hero of mine. I met him properly in Stratford when I was designing Deborah Warner's Titus Andronicus [in 1987]. He doesn't remember, but we had a long conversation about religion at a first-night party.

Thirteen years ago we met again when he was looking for a designer. His agent asked me to leave a portfolio, which I hate to do, so I rang him at home and he was delightful and told me to come round. I went very nervously and we sat down in his front-room. It was the middle of the afternoon and he poured a large whisky for us both, which I was very grateful for. I've never seen him drink again so it was kind of him to put me at ease like that.

I always thought we'd get on – or at least that I would like him – because we'd had such an interesting conversation in Stratford. I stayed an hour, talking about all kinds of things. Within a week he had rung me to ask me to design Nabucco for Zurich, which was a big break.

Working with Jonathan has made a huge difference to my whole life. He is one of my best friends, has taught me vast amounts and has introduced me to painters and photographers I hadn't heard of, but who are now such a part of my life they feel like second nature.

He is hugely knowledgeable about so many things – neurology, philosophy, history of art. You do tend to have serious conversations with Jonathan, but he is also very, very funny. He is never flippant, but he sees the ridiculousness in things.

He is incredibly kind and warm while also self-contained and unsentimental. We both care enormously about what we do without being emotional about it, and I think the reason we work so well together is that we agree on the fundamentals of life.

For the first projects I was in awe of him, whereas now I feel a lot more confident about what he will like. It's still very exciting if he is pleased, though. There's a word that he uses which I suppose sums him up. When he has seen something he thinks is magnificent, he says it is "dazzling". When he describes something as dazzling, it's always a wonderful moment.

Sir Jonathan Miller, 75, is a theatre and opera director, neurologist, writer, sculptor and television presenter. He first became known as a member of landmark comedy show 'Beyond the Fringe'. Since then he has presented television shows on the arts, philosophy and science, held the post of associate director at the National Theatre and established himself as a ground-breaking opera director. He lives in Camden, north London, with his wife

I don't remember clearly the first time I met Isabella, but I think she came to my house and I looked through her designs; I do remember being very impressed by them. Her work was ingenious, inventive and modern but at the same time it wasn't afflicted by idiotic "concepts": modern without being modernistic.

We had a long and amiable conversation and it was clear she was as susceptible to historical art references as I was, and that she could react to my suggestions. Unlike a number of other designers who want to inflict their ideas on you, Isabella has always wanted to work co-operatively. We began to work together almost immediately and I have since worked with her to the exclusion of any other designer. You can never be absolutely sure in advance who you will work well with, but each time we have undertaken a project together it has got better and better.

Isabella is an extremely cheerful person and our mode of working is easy and convivial. I tend to give her a set of visual references and we look through them all together, then she will go away and produce the models. She is very good at alluding to various sources, as am I, so we bounce off each other and it is very productive. It's rather like playing rugger – if you can make a pass to someone and they can catch it and run with it, you score a try. It feels spontaneous and effortless, although it's clearly not without effort on her part, as she works extremely hard.

We've been around the world working on productions together – Tokyo, Munich, Zurich, Berlin – and it's all been fun. We enjoy the scene wherever we are and go to a lot of art galleries together. We both take a lot of photographs, then swap our images a great deal.

Isabella and I are old friends now, and our families have become friends too. I get on with her husband and she gets on with my wife and with my eldest son in particular. If we're not working on something we still see each other regularly – she'll drop over for tea or for dinner at my house and my family and I have been up to her house in Yorkshire for holidays. It's a professional relationship that has become a very amiable friendship for us as well as for those around us.

'The Elixir of Love' is at the London Coliseum from Friday for nine performances (