Truly, I’d hoped boyfriend jeans had gone away, having not seen much of them since their heyday in 2008, when the likes of Katie Holmes wore them day in, day out.

But I was wrong. Earlier this week, Sienna Miller wore a pair on the streets of New York. Oh dear.

Now, Sienna is a beautiful, very thin young woman. She looks good in almost anything. But even she looks dreadful in these boyfriend jeans.

OK, why? Let’s do a point-by-point analysis. First, a pair of man jeans are cut to accommodate a man’s thighs; therefore they are way too boxy. Then the holes at the knee are too Eighties, the belt is just ghastly, and the shoes are way too low. She has rolled them up, but not enough!

We need more sexy calf. As it is, the whole shebang shortens her silhouette, and is really insulting to anyone she meets. “Hello,” this outfit is saying. “I can’t be bothered to iron, or buy my own clothes, and you will just have to deal with it.”

Looking at the other celebrities who have sported this dreadful look in the past four weeks, I notice, too, that the only women who look vaguely halfway decent in baggy jeans, which also sag at the buttocks, are cadaverously thin, viz: Sarah Jessica Parker. Her boyfriend would have to be Mahatma Gandhi for the former Carrie Bradshaw to even halfway fill them up.

Now note the BFJ on Hollywood actress Ginnifer Goodwin. She is normal-sized, but the wide jean makes her look bigger than she really is.

Unless you have super-long legs, a rolled-up cuff makes you seem of Dachshund proportions. There is a reason the boot cut became so popular among mere mortals — it covered a bit of your boot or shoe, and thus lengthened the leg.

My rule for boyfriend-jean dressing is that the rest of you has to be very feminine and groomed, and not supersize: ie, a tiny tank or a sheer shirt, and heels. Flats only work if you are very tall. Yes, boyfriend dressing is a minefield. It has been promoted as being easy to wear — the opposite of body con, which means showing your kidneys every time you step out the door — but it can be very unfeminine, and difficult to pull off.

And, of course, none of us ever actually steals clothes from our male other halves. They are too tight to ever spend money on the right labels, cut and fabric, and have no taste to speak of.

If I had stolen my ex-husband’s clothes, I’d have been dressed in a Gap hoodie, oversize jeans from Next, smelly trainers and bald socks by Adidas. That is a “No”.

But the idea — that we choose something a bit sloppy and outsize — can be a good one. I opt instead for skinny jeans over shoe boots, and a boyfriend jacket. I got mine in the Prada sample sale: it is soft, supple suede, the colour of the Sahara desert, and looks wonderful with the cuffs turned up, over a strapless evening dress, jeans, or a pair of shorts for summer.

A last point: the very term “boyfriend” anything gets my hackles up. We women can buy our own clothes, thanks very much.

Top-ten tips for buying jeans:

1. If you have to lie down on the bed, using a coathanger to pull up the zip, the jeans are too small.

2. If you have any sort of fat tummy or gut, the hipster skinny is not for you. Even an inch higher waistband will keep everything under control.

3. Never buy a vintage pair of jeans: there is no stretch, and you will feel as though you are about to die.

4. The best budget jeans are the denim jeggings at Gap: £49.95 (Dh278). If you go cheaper than this — hello, Primark! — the denim will be so thin, people will think you are wearing blue tights.

5. The best expensive jeans are Seven for All Mankind: they fit well, and last for over a decade, even if you are really tough on them, ie, have puppies on your lap daily. They’re available from Selfridges, Harrods, Way In and Asos.com: the boyfriend jeans are £200, but I prefer the high-waist boot cut, £185.

6. An inky or black jean must be exactly that: fading is bad. Try the new non-fade jeans from Marks and Spencer, in stores from July, and the buttock-enhancing jeans, also in stores in July, all under £50.

7. Do not go back. The relaunched Levi 501 is a mistake. I tried on my pair bought in the late Seventies, and they are just awful! Waist up near my neck, far too wide in the leg, no stretch at all.

8. Try white denim for summer, with a gentle boot cut and a navy blazer: really classy, great on holiday, and you will feel like Liz Hurley.

9. If you must wear boyfriend, you simply must dress up everything else: heels, make-up, and a top that is not a plaid shirt, but is instead fitted and feminine, even cropped!

10. Do not iron jeans with direct contact as a crease or shine is a killer: use a damp tea towel as a buffer. Always wash on the denim setting, add conditioner, and line-dry on a hanger.

— Daily Mail