The 'stealth wealth' item that will make you look richer without spending a fortune, revealed by SHANE WATSON

Perhaps the two most surprising developments in fashion over the past few years have been the rise of the smart trainer and the smart stealth wealth sweater. But it's the SWS – the sweater that looks expensive but doesn't actually have to be – that's still on the up and on course to being the most useful and versatile piece in your wardrobe.

Five years ago you would never have seen a woman in a sweater at a party, but at one recent event the room I was in was split between slinky top wearers and women in SWS. There were decorative ones; pretty, fine gauge ones; cool Phoebe Philo at leisure ones (cream or pale grey with a pulled up turtle neck and pushed up sleeves, flopping over a pair of pin stripe trousers).

Elevating your look just enough, without making it too fancy or formal, is the trick of modern smart casual dressing and the item that pulls it off with minimum effort is the stealth wealth sweater. This classy striped jumper costs £325 from navygrey.co.

H&M's grey cable knit makes an effortless outfit and costs just £19 from hm.com. The SWS gets everywhere now, from board meetings to cocktail parties or weekend lunches. They're easy, versatile and they add a certain air of nonchalant luxury – the kind that Gwyneth Paltrow showcased so memorably at her Utah ski crash trial in 2023, when stealth wealth captured the imagination of us normal civilians.

Fashion designers now treat SWS with the same respect they once treated silk blouses and tailored jackets, sending them down the spring catwalks draped over the waistbands of skirts, hovering around the hips of trousers and slung around necks and under the lapels of jackets.

Everyone wants one. It doesn't have to be cashmere but it requires something in the mix – could even be mohair – to give it the lush texture that separates this sweater from your regular weekend jumper. Acrylic or cotton will not cut it. You want it to be versatile too, so I'd say skip the styles with pouffe sleeves.

Likewise the current fashion for Norwegian patterns and 'fisherman core' rustic jumpers is not for the woman after a luxurious everyday sweater. There are two broad types: the classic cool all-rounder and the special hit (remember we're talking about stealth luxury here so jewel trims, patterns and decorative buttons are all off the cards).

The best SWS all-rounder, and one I'm always on the hunt for, is a well-cut turtleneck. It's got to be a turtleneck because the neck is what delivers the elegant silhouette, plus neck coverage, and you can forget about lumpy shirts underneath and just wear a layering top.

You want one with structure (a ribbed neck, to stand up) in a five-star neutral colour – navy, grey, cream or camel or brown (a lot of the quality sweater brands like Navy Grey only do sweaters in these colours, and red). Keep ribbing for the neck and cuffs: it's hard to find medium weight ribbed jumpers that don't add inches.

Labels that are good for luxury turtlenecks include Navy Grey (navygrey.co) and Cos does a nice one in navy (£250, cos.com). Various labels (notably Me+Em) do sweaters with detachable turtlenecks, doubling your options at a price. The luxurious striped jumper is £175 from meandem.com.

Navy Grey does a huge range of luxury turtlenecks, including this navy one for £325 at navygrey.co. Marks & Spencer is a solid place to start for all sweaters, including cashmere, in all styles but they do a luxe-looking textured rollneck in yummy cappuccino (£25, marksandspencer.com) that's just the job. I also like Mango's mid grey crew neck (£25.99, johnlewis.com). Wear a luxey looking crew neck with a white or striped T-shirt peeking out under the hem for a classic stealth wealth look.

Cable knit has credibility (in the right wool blend it looks expensive) and a round neck cable knit in grey always looks chic (£20.99, hm.com); add another around your neck for extra luxury. Stripes are having a big moment this spring and, provided you stick to the classic palette of black or navy and ecru in a good texture, you'll get lots of wear out of these. Try H&M's soft mohair striped sweater (£54.99).

Pale but not sugary colours such as winter yellow or apple green are very stealth wealth (they score high on dry cleaning bills) but bear in mind the paler the colour the more the quality shows. An easier option – and a big theme for spring – is mixing up surprising shades (peridot, petunia, cinnamon) – and this is where the SWS comes in.