Talk of 'day to night' dressing is endless in fashion, but for spring, designers were working in reverse, bringing sleepwear into the waking hours.

There was the slouchy separates route, as seen at Dolce & Gabbana, or the negligee-for-day approach, championed at Celine.

So the question is, which pyjama party will you join?

Whichever you decide (why not try a bit of both?), these are the pieces that will have you sleepwalking in style...

CALL IT A NIGHTIE

If you only buy one item of clothing this season, it simply has to be a slip dress.

The undisputed hero piece of the season, strappy silk dresses showed up on countless catwalks, including Calvin Klein, where Francisco Costa's Thirties-via-the-Nineties pale bias-cut frocks paid homage the brand's own history and were styled with box-fresh white trainers, proving that slinky dresses can work for day too, particularly when they're midi-length.

At Celine, shorter styles with risque black lace edging were made for cocktail hour.

Pale hues - think ivory, dove grey, blush pink - look very chic paired with delicate silver jewellery and black strappy heels.

Shorter lacey tunics or camis can be worn over silky trousers for a bit more coverage - plus-size brands do these kind of wide-leg styles really well.

For a final tongue-in-cheek touch, add fluffy boudoir sandals.

:: Related Acacia Dress, £205 (www.relatedapparel.com)

:: River Island Black Lace Detail Slip Dress, £38 (www.riverisland.com)

:: Lace Trim Cami by Laura Scott, £20 (LookAgain.co.uk)

:: Mat Pleated Wide Leg Trousers, £89.99 (Navabi.co.uk)

:: Luxe High Sandal by Unique, £125 (www.topshop.com)

KICK OUT THE JAMMIES

Dolce & Gabbana are known for their sexed-up, flesh-baring frocks, and while there was no shortage of those on the SS16 catwalk, there were also some very demure designs, including three pairs of floral pyjama-esque sets and a stripey kaftan, almost certainly inspired by a Victorian nightshirt.

Invest in slouchy button-down co-ords now and you won't regret it - the shirt will become an office staple paired with block-colour skirts, and you'll be wearing the trousers right through to summer.

Likewise, a silk 'pie crust' shirt (think high-collared and ruffles), as seen at Alexander Wang, looks great with jeans and mules, and with a longer gown-like shirt, you can go tights-free.

Shoe-wise, it's got to be the flat that's taken over from the ballet pump - what could be more trend-appropriate than a slipper?

:: French Connection Sundown Silk Shirt, currently reduced to £48 from £120, and matching Flared Trousers, currently reduced to £36 from £120 (www.frenchconnection.com)

:: Jigsaw Linear Flower Silk Shirt, £129 (www.jigsaw-online.com)

:: Persona by Marina Rinaldi Striped Silk-Blend Shirt, £119.99 (Navabi.co.uk)

:: Piped Silk Shirt, £75; Bloom Print Ankle Grazer, £65; Bertie Pumps, £65, all Crew Clothing (www.crewclothing.co.uk)

:: Dune Silver Garnish Slipper Cut Flatform Shoes, £75 (www.dunelondon.com)

GET THE LOOK

Actress Zoe Wanamaker, 66, embraced the boudoir trend at the Olivier Awards, in a beautiful floor-length silk gown, proving this is a trend that works for all ages. Ghost has a selection of dye-to-order satin dresses, so there's a neckline to suit everyone.

:: Ghost Sylvia Dress, dyed to order in Ivory, £225 (www.ghost.co.uk)

BUY IT NOW

Trust premium slipper makers Chatelles to come up with what can only be described as the Ultimate Slipper Collection. Designed in collaboration with US Vogue style editor at large Elisabeth von Thurn und Taxis, and crafted using couture techniques in the brand's Paris atelier, the trio of velvet, satin and raffia creations are priced from around £300. But the sturdily-soled shoes aren't just for lounging around indoors, so you can be sure your compliment-to-cost ratio will make them worthwhile.

:: Chatelles x Elisabeth Thurn und Taxis Seraphin Slippers, 399 euros (around £322), (www.mychatelles.com)

FASHION FLASH

:: NO HELP ON THE HIGH STREET

More than half of women over 70 (52%) say they're being let down by the high street, as staff are unwilling or don't know how to give them advice on finding the right size - according to a new survey by classic fashion brand Carr & Westley. The poll of 1,000 over-70s also found that 47% say they don't like using changing rooms, while 36% have stopped purchasing new clothes entirely because they find the high street intimidating - which means retailers are missing out on potential income, too.

:: BIKINI BABE AT ANY AGE

But not all brands are neglecting an older audience - JD Williams, which has long championed fashion for mature women, has just announced Angie Best as the face of the new Melissa Odabash swimwear range, designed with 50-plus figures in mind. The 63-year-old model says: "Women shouldn't have to feel they need to hide away on the beach once they hit 50 and this range proves that. I hope women see these pictures and feel inspired to jump into a bikini or one-piece this summer!"

STYLE STEAL

Even dressing gowns got a look-in with the slumber party trend, as loose silk belted jackets were worn open and billowing at Givenchy. A jersey kimono is a great spring cover-up, and the Boohoo Plus Maisy Belted Kimono Jacket is now down from £20 to just £10 (www.boohoo.com).