Do you regularly shoot pheasants? Spend much time in vast, draughty country houses?
Unless the answer to at least one of these questions is yes then you don’t need to dress as if you’re off for a weekend at Downton Abbey. Tweed jackets are traditionally made from wonderful thick and slightly abrasive fabric built to keep out the cold and the rain.
For the man about town a lighter, more refined cloth is a better choice. The luxurious alternative is a lightweight tweed with a bit of cashmere woven into it, because this means the fabric will feel soft, and the jacket won’t be too hot. Tweed’s great appeal is that it comes in such a variety of colours and patterns, from the very bold (which are probably best kept for days at the races) to the very muted.
A useful approach for modern men is to go for a stealthy tweed, which retains the fabric’s easy informality, without speaking too loudly of life in the shires. Blue tweeds are a great place to start, perhaps in herringbone, or a speckled Donegal. Start with a two button, singled breasted jacket to wear like a blazer, and think about having it cut so that you can wear a Shetland sweater underneath it, which means that it’ll act as both a jacket and a coat in all but the coldest weather. Worn regularly with faded jeans, or slim cords, the jacket should quickly start to feel like the most comfortable thing you own.