GOOD FOUNDATIONS

I'm a self-confessed foundation addict - it's partly because I like quite a groomed beauty look, but it's also because I'm long past the age where I dabbed a spot of concealer under my eyes and left my skin bare. Somewhere in my late thirties I found my skin became less even - and if I believe what I hear at the press launches for new anti-ageing products, I'm not alone, which is why there's suddenly a vast array of products which promise to fade brown spots and tackle redness and so on.

This Dior Forever foundation is my current favourite: it provides enough coverage to give an even complexion and reflects light away from fine lines - it also has skincare benefits built into the formula which keep the skin moisturised so that you don't get that ghastly five thirty thing when you look at yourself in the office loo as you're about to go home and realise you look four hundred. Anyway, I like it - it creates an elegant finish without screaming 'I'm wearing a tonne of foundation'

Lauder's Double Wear Light is, apparently, one of the country's top selling foundations - until I discovered Dior Forever it was my favourite, and I'd still wear it if I were going for a hectic night out because it lasts and lasts and lasts. It also photographs well (I'm sure you're not nearly as vain as I am and don't ruthlessly manage all your photographs so that only the ones that present one's best side ever appear: Mr Trefusis only posted one picture of me without make up on Facebook - he soon saw his error)

However, I do think proper foundation only really works in mild to cold weather - the minute the sun comes out everything changes and one goes immediately from perfectly groomed to over-made-up - think Kate Middleton. OF course, this year, in the UK, we can get away with wearing the makeup equivalent of black opaques well into June unless something changes radically, but tomorrow I'm off to Marrakech for the weekend, where foundation will not only look wrong, it will melt off my face. Not only that, but Newby Hands, beauty guru and Bazaar's Beauty Editor At Large has been telling me for ages that going bare skinned looks much more modern, even with made up eyes or lips. I'm not at all ready for no make-up - in the same way as I couldn't bare my legs - so I'm experimenting with BB creams, which seem to be all the rage. They're popular because they're a multi-tasker, offering the combined benefits of a moisturiser, a sun-screen and a foundation, to care and perfect the skin in one easy step. The Lauder one is based on their ever-popular DayWear moisturiser and has a beautiful satiny finish and an SPF of 35. I liked it, but despite what Newby said about the no-makeup look, I didn't feel modern, I simply felt a little too nude.

I slightly prefer the Clinique BB cream  - it's less moisturising than the Lauder one and it's only SPF 30 (not sure my skin will know the difference) but it's a little thicker and has more staying power. Unlike Lauder's, you definitely couldn't use it as a primer under your usual foundation, but it has more staying power. It's better than a tinted moisturiser and it's the one I've packed for my Morocco trip tomorrow in the regulation clear polythene bag. Actually, my clear polythene bag is rather large - I can't travel without a beauty product for every eventuality - are they going to clobber me at the airport? I guess I'll find out.

On balance, I think BB creams are perfect for thirty somethings who want a little extra perfecting and are pushed for time enough to want a multi-tasker. For me, they're good for a weekend in the park with Trefusis Minor and The TT, but for work and for when I'm not loafing round West London in jeans trying to avoid looking like a Boden advert.  But Estee Lauder's new (ish) Invisible is absolutely the halfway house I think I've been looking for: it's almost completely weightless so you don't feel it on the skin and the special magic formula adapts the colour when it's on your skin in a fabulously chameleon-like way, making the match absolutely seamless. It's the only foundation I've ever worn that's elicited spontaneous compliments about how good my skin looks* - even Newby didn't think I was wearing foundation.

*someone at work asked if I'd had 'something done' the first time I wore Invisible - I'm not absolutely sure it's a compliment but I took it to mean that it did its job and glossed over all the wrinkles and crevasses that are otherwise visible on the Trefusis fizzog