The It girl's guide to mastering party style- and why it's fine to dance in trainers

Party season, Julia Restoin Roitfeld says, is one of her favourite times of the fashion year. “The best part of going out is getting ready,” she laughs. “Doing my makeup, even putting on earrings, it’s such a luxury when you normally have no time. I have a little girl [Restoin Roitfeld’s daughter Romy Nicole is five] so getting ready to go out with friends can feel like an indulgence and when I do it, I like to do it properly. With the good music on and a little glass of wine, you know?”

The 36 year-old model and fashion designer is likely one of the most-invited people on the international party scene, a factor that has, over the years, turned her into a magpie for clothes with good sparkle. This weekend, she unveiled a new collaboration with the British high street favourite Warehouse, after road-testing and selecting the best pieces from their festive fashion range to compile an edit of Christmas partywear pieces that won’t date. Perhaps unsurprisingly, almost everything on her rails is blitzed with dark, glamour-packed embellishment.

“Who wouldn’t want to shine at a party?” she laughs, when asked if she has an addiction to sequins. “I think party dressing is all about textures and there are so many great ones to try. Velvet, lace, devoree, sequins, embroideries… that’s what I love. I like to wear a lot of black and navy, but with the glitter you still are noticed.”

Restoin Roitfeld doesn’t apologise for the fact that she reaches for the same things year after year. Knowing what suits you, she says, is a far more effective way to express your personal style than pandering to new trends. “This is why Kate Moss has always had the best party style,” she says. “I’m not very original to say that, but I Google all of her 90s outfits for inspiration. They’re classic, rock ‘n roll and elegant. She always had the perfect little black dress, too.”

Investing in classics is also more budget-friendly way to shop, she notes. “It really annoys me when people say you can’t wear the same dress twice. What if you love it, or you just can’t [afford to] buy a new dress all the time? I’m very lucky that I get to borrow clothes sometimes, but I’ve worn the same slip dress to several parties over the years and nobody notices. Once with a ponytail, once with hair long, once with big hoop earrings... these things cost nothing to change.”

Metallic spot top, ￡36, warehouse.co.uk

“I look at my mum [the French stylist and former editor of Vogue Paris, Carine Roitfeld] and she rewears the same things all the time and she doesn’t care. She’s like, ‘it looks good on me and I know it looks good on me’. She always tells me it’s better to be too much than not enough, though. You’ll always feel better if you’re overdressed than if you’re underdressed when you arrive at the party.”

Restoin Roitfeld has a practical set of tips when it comes to accessorising, essential for anyone heading off to an office Christmas party this year. “Big shiny earrings will always bring a glow to your face. I’d choose them over necklaces which can be complicated with different necklines.”

And on her feet? “I love heels but for the best party I ever went to I wore a sexy, shimmery black dress with Nikes. It was the CR Fashion Book party with Circo Loco in Ibiza and I was dancing on the heels for three hours before I switched into the sneakers. It was the smartest move. So many times I’ve gone home because my feet hurt, but now, I don’t care to be tall in heels after a certain point. When the music is good, all you should want to do is dance.”