I've tried hundreds of trench coats – here's how to find the right one for you

If the trench coat was human it would be Joanna Lumley – quintessentially British and mostly marvellous, but occasionally off-key. Remember when she hosted the Baftas?

It was Lumley who introduced me to the potential sexiness of a Burberry trench when she was in The Pink Panther circa 1983. My version came from Bus Stop and missed the mark by several continents, as so many trench coats still do. They’re too boxy. Too bulky. Too laden down with flaps or epaulettes. They can even be too navy. Who knew? I thought navy would be more flattering than camel – until I tried on my hundredth. I’m not saying navy can never work, but the cut has to be exquisite. And that means one thing, or rather hundreds of them: ££££.

As for camel? It’s an impossible shade if you have yellow tones in your skin or are very pale. In which case you have to work your way around the camel spectrum until you find something that doesn’t make you look like a potato. For me, that’s khaki or olive.

My other trench coat lodestar, Kate Moss on the many occasions she wore Burberry with nothing underneath, is another dream-on scenario. Nothing underneath is how a trench coat works best, but – and feel free to correct me – it’s not really for the likes of you and me on the daily commute, is it?

So apart from the colour issues, the looking best when you’re naked beneath it, and the fact that its major selling point (keeping you dry) isn’t always a given, what is good about the trench?

The fact that in the right shade, cut and fabric (showerproof ideally), it’s a wonderful piece of classy, androgynous kit. It also requires almost nothing in the way of accessories, other than long boots, slingbacks (if you’re aiming for the Christine Keeler vibe) or trainers.

The best trench fabrics are stiff enough to hold some shape and for the collar to stand up but not oppressively heavy. Or they’re artfully floppy – good if you’re wearing a sleeveless one as a dress. Unless you’re statuesque, opt for slimmer lines and a length that works not just on your frame, but with your clothes. Most trenches aren’t easy to take up.

Some Macintosh trenches have smart piping or detachable linings that make them much cosier, year round. Not cheap, but a long-term investment. Alexa Chung has done a wonderful waxed trench for Barbour. And the Jigsaw one I’m wearing here is a lovely olive-beige, showerproof, cotton twill, with a leather-look panel.

It’s worth stalking the resale sites, too: Hardly Ever Worn It for instance, has a good selection of Burberrys. Although even second-hand, they cost between £400 and £600 – a sign of how well they wear.

Five of my favourite buys

From left to right: wax trench coat, £499, Barbour by ALEXACHUNG; water repellent cotton, £895, Mackintosh; water repellent cotton twill, £389, BOSS; sleeveless turquoise, £115, Cos