One of the biggest mistakes men make is wearing T-shirts. I understand why youíd want to wear them, especially if youíre a single man. Thereís no ironing. But most guys need to have a collar around their neck for height.

If youíre in doubt about how to wear your hair, get a non-haircut: a relatively short, nondescript one. If you try for stylish hair, you can make horrible mistakes.

Women should always be entertained. My wife hates it when men at a dinner party lean in front of her or behind her and have a conversation as if she doesnít exist.

If youíre going to a formal event, you have to dress correctly. But if you get there and realize people arenít wearing bow ties, you can put yours in your pocket.

On a young guy, two days of not shaving looks very cool. But as you get older, it looks like youíre trying too hard, especially when youíre going gray. A proper beard is fine.

In London, weíre not so passionate about how we look, as opposed to the Italians, who are very self-conscious. Weíre not stylish dressers, but weíre good on ideas and on freethinking.

You can learn from people who dress in an interesting way, like Daniel Day-Lewis. You can see him on his motorbike in jeans, a checked shirt, and a leather jacket. And other times heíll have on a custom-made Scottish-plaid suit.

Generally speaking, I wear a suit every day, because my suits are custom-made. They are comfortable. They move with me.

I donít have a BlackBerry. I carry a notepad and a pencil—and I donít use a mobile. Iíve reluctantly moved to a digital camera, but only because they make them so nice and small now that they donít spoil the line of your suit.

Iím very happy if a man smells like himself. But if he does wear a scent, it shouldnít be too attention seeking. The people on the other side of the office shouldnít be able to smell you.