Lazy way to look chic? Sling on a neat knit: How to dress like a grown up with SHANE WATSON 

May is when you make the switch to summer sweaters, and not just because you need a lightweight layer when the sun goes in.

Summer sweaters are the lazy dresser’s sling-on look transformer. They can add saturated colour to a neutral outfit — a bright pink or turquoise sweater under a plain camel coat, for example, makes it look new and modern — or a splash of something clashing.

There’s a particular skill in mixing prints together in one outfit and I don’t really have it, but I can hold a bright purple sweater up against a navy and brown print and watch it come alive.

I know that a soft, almost-waisted sweater makes an ordinary A line skirt look elegantly casual, and that a tank top in a zinging colour can make a regular shirt and trousers look daring and different.

And you get all that from wearing a summer sweater. You can just as easily wrap it around or tie the sleeves across your front like a cross-body bag strap.

Sophie Turner channels her inner rock chick in a loose, stripy knit paired with black leather trousers and high heels 

I love the contrast of a wool sweater wrapped around your neck when you’re in light shirt sleeves and the security of it draped across your shoulders in a sleeveless top or a short-sleeved T shirt.

You can wear a plain black top and trousers with a sweater around your shoulders and switch the colour depending on your mood: electric blue for the bar, skin-flattering coral for the candlelit dinner.

A wool wrap works, too, and I’m partial to an oversize scarf, but a sweater does two jobs and feels more relaxed.

Not any old sweater will do if your aim is to dress up an outfit and make it look new.

The secret with a summer sweater is to keep it structured and neat and avoid baggy or longer styles. Now trousers and jeans are higher waisted, you want a sweater or cardigan that sits on or just below the waist to keep the look neat.

A good all rounder is a sweater with a V-neck opening and a collar because it’s flattering and elegant and looks particularly good with skirts, plus you can wear a vest underneath or nothing.

Marks and Spencer does a great cashmere collared jumper (£89, marksand spencer.co.uk) in camel, bright emerald green or black — all colours you’ll get plenty of wear out of — and it will still look good next year.

The ribbed cotton versions are cheaper (£22.50), but they don’t hold their shape as well and don’t give you that relaxed yet luxurious look. Otherwise Uniqlo’s seamless cashmere crew neck is on sale (£79.90, uniqlo.com) and comes in a bright cherry red, orange, cornflower blue or that print-igniting purple.

Liv Tyler wears a pink and black stripy knit with black trousers and patent ballet flats

Penelope Cruz poses in a cropped white Chanel cardigan with the brand’s signature silver buttons

Another place to look for bright knits is British brand Nrby. Its chunky tank tops come in Queen Camilla’s signature blue and a cracking pink and orange and purple stripe (£89, nrbyclothing.com).

This is also a good moment to invest in a smart cardigan, cut like a cropped jacket and sometimes embellished. Boden does a classic navy boxy cardigan with gold buttons and pockets (now in the sale £96, boden.co.uk), but its dark grey, cropped, wool cardigan embellished with crystal bug buttons (£120) is the summer sweater you’ll still be wearing to parties come winter.

This is the new way to wear knitwear, buttoned up and cropped, with just a plain layer underneath.

Stripes can also be smart.

A round-neck sweater with button cuffs in black and ecru stripes (£32.99, zara.com) looks chic with knee-length tailored black shorts.

I also like a striped buttoned up cardigan (£95, sezane.com) in ecru with navy stripes (the other way around is more wintery) to wear with smart jeans or a midi skirt.

Some things to watch with a summer sweater: you don’t want it to be too thin or too open weave (either way, see-through) and you’re better off sticking to strong colours or neutrals — pastels can look droopy.