The maxi shirt dress is your smart-casual summer hero

Whether you’re currently mourning the reported death of the floral dress or loyally sticking with yours regardless, in the shop windows on my local high street there’s been a noticeable shift away from dresses, and towards casual, slouchy separates – wide leg linen trousers, pyjama-y coordinating sets, lots of baggy denim. But while I’m personally in the camp leaning away from the printed midi dress – at least for the moment – this leaves a dress-shaped void in my wardrobe. What to wear for a day of meetings, or afternoon at a gallery, or when meeting a friend for a nice lunch that might just roll into a whole evening?

Enter the shirt dress, with one crucial update: the best modern iterations are MSDs – maxi shirt dresses, finishing right on the ankle bone. Riding a bicycle to lunch in the Hamptons recently, Jennifer Lopez was photographed wearing a gauzy green-on-white printed version by Dior. It was her 55th birthday, which perhaps explains the $3,400 price tag (though not why she would risk it so close to a greasy bike chain). Meanwhile, on the same day but on a different continent, Celine Dion (in Paris) also chose an ankle-length Dior shirt dress. Hers was black, with a little more fabric and volume in the skirt, but both shared the same hourglass cut of the 1950s “shirtwaist” originals.

“I like to wear them loose and with flats,” says fashion stylist Esperanza de la Fuente, “and over a bikini on holiday too. They’re very versatile, from beach to dinner – just switch the accessories.”

Vintage shirtwaist dresses were most often cropped just below the knee, but that makes for tricky shoe choices, and feels daytime specific. But an ankle length shirt dress looks just as good with flats as heels, and unlike a shorter style is easily re-accessorised for evening, and not just on holiday, but in the city or the office too. Both the shape and the length make it feel elegant – but not fussy. Lopez and Dion both wore those with hair pulled sharply back, and a few small bits of jewellery, emphasising the simple elegance of the dresses themselves. With this summer’s go-to ballet flats (like Lopez) or, a little dressier, slingbacks (Dion), a MSD is the wardrobe all-rounder that will work for the rest of the summer and then – with a few more layers – well into autumn.

Add “simple black flip flops, sleeves rolled up and some great rings on, a big woven leather bag and some black sunglasses,” says social media creator and book club host Lizzy Hadfield; “and it’s a perfect day to night look too.”

The bonus of a button-through is that a dress-code-thwarting restyle is just the matter of buttoning up a little more, or a lot less. Back in May, Anne Hathaway illustrated this in a white cotton shirt dress, floor length and darted at the waist – and buttoned only there, creating a thigh-high split and off-the-shoulder possibilities. Hathaway’s dress wasn’t Dior, but Gap – £120 (though very quickly sold out). Thus unbuttoned, and with her hair down and some stonking jewels on, her MSD was red carpet-wear for an event in Rome. So, belted at the waist and unbuttoned at the collar and with your own stonking jewels (costume, in my case) and a satin or velvet bag, your own shirt dress can certainly meet a cocktail dress code.

And for those of us in neither Paris, the Hamptons nor Rome, but are trying to navigate this sticky British summer time; “at the moment I’d be letting it simply hang – no belting,” says stylist Monikh Dale. “Adding a large stone necklace as a focal point, simple flip flops which seem to be the chicest sandal to be seen in, and a suede bag.”

That vintage inspired, nipped-in at the waist silhouette won’t be to everyone’s taste. If that’s true of you, there’s still an MSD to suit. Swap the full skirt for straighter lines, as if a men’s tailored shirt had been carried on right to the floor, and you have a more relaxed shape with just as much versatility. Or perhaps more: Katie Holmes wore her long sleeved black Banana Republic MSD completely open, layered over a white tank and pale pink trousers – a sort of duster coat for days that are too hot for heavier layers.

So, to find the right one for you. Stiffer fabrics like cotton will keep their structure, and so might look a little more architectural on. That can work particularly well for more angular or tall body types: I’m all curves, so find that the rigours of cotton swamp me and prefer a fabric with a bit more drape. The right length on the ankle is important, and will take a bit more shopping around if you’re tall (start with Scandinavian brands like Arket and Cos on the high street, who usually cut long), but might require hemming at your local dry cleaner either way. Just cropped enough to show shoe and ankle bone is spot on, to get the most mileage from this smart-casual shapeshifter of a dress.

Five of the best

The classic neutral

Organic cotton, £140, The White Company (the sand colour as all sizes are available) 

The cinched waist

Recycled polyester mix, £155.35, Karen Millen 

The bold bright

Linen mix, was £159 now £75, Whistles 

The summer stripe

Cotton, £750, Borgo de Nor at Net-A-Porter 

The graphic print

Cotton, £125, Boden