‘The moment that I realised that the camera was zooming in to a tight close-up of my virtually naked face, I had to forget that I was not exactly looking my best’

I've recently been working on a film, in a role that I found both challenging and incredibly fun. The fun part was that I had to do a Kentucky accent, something I've never done before, but with its spectacularly drawn out vowels and added consonants, as long as you don't veer into Forest Gump territory, it can be (or so I'm told) rather beguiling. Even more fun, were the lovely, smart, talented people that I was lucky enough to find myself working with.

The first challenging part was that we were filming in an abandon psychiatric facility. It was spooky, atmospheric (all perfect for the tone of the film) but also freezing cold. Watching the crew go about their work wearing coats, gloves and hats suited for a polar expedition, whilst the cast stumble around, resisting the urge to shiver, in their flimsy outfits is actually pretty standard-fair for film sets. The biggest challenge of this role for me was that I was playing a real person. As I write, the powers-that-be at the film company tell me that the movie is still 'embargoed' and that I'm not allowed to discuss it publicly yet, so I'll have to be a bit careful and not reveal too much, but this was the first time I had played a non-fictional part and therefore had to look as much like the real woman as possible.

This meant relegating my appearance to the costume designer, makeup artist and hair designer. Unlike a normal movie role, I had no say whatsoever in how I looked. 'Flattering' was not a consideration. And when I looked at myself in the mirror at the end of my hour in the makeup chair, with my 70s wig, nylon dress and virtually no makeup on, I must confess I was slightly horrified.

I should clarify that I almost always wear makeup. Even days when I'm at home alone, if I need to be productive, I find that 'putting my face on' helps me to concentrate. And I'm sure I'm not the only woman who has perfected the art of The No Makeup Makeup Look. Until really quite recently, anyone who has said to me "You look great with no makeup on" doesn't realise that they haven't actually seen me with a bare face, just a skilled representation of a more flattering version of that.

So, the moment that I realised that the camera was zooming in to a tight close-up of my virtually naked face, I had to forget that I was not exactly looking my best and only concern myself with the heartbreaking situation that my character was facing in that scene. Basically, I had to get over myself. And whilst I'd never want anyone to think "Blimey, she looks a bit rough in this", I would also never want to be a diva who's willing to sacrifice the integrity of her chosen career because of vanity.

As this is for the January issue of our favourite magazine Cotswold Life, it seems appropriate to deem my determination to 'Get over myself' as a New Year's resolution. I shall try to apply that general rule to the more everyday aspects of my life.

If I'm asked to join friends in some sort of public swimming situation, I will fight the inclination to decline due to the horror of showing myself in a swimming costume. True, in the 80s there was a poster of me on a beach wearing a very skimpy bikini, but that was when I was in my twenties, hadn't had two children and was being photographed by a very skilled photographer.

If my kids ask me to ride a roller-coaster with them, I'll really try to stop myself from offering my usual, admittedly cowardly position of Guardian of the Coats and Bags on a nearby bench and actually give the roller-coaster a try.

And if a light bulb goes out at my house, rather than ignore it and pretend, with my inexplicable reluctance to change a light bulb, that I don't mind the dim light in that corner of the room, I'll just change the damned thing right away.

But perhaps the best way to 'Get over myself' is to stop all this navel-gazing and just, well, you know... get over myself.