When Coco Chanel suggested checking oneself in the mirror before leaving the house, and removing one item, she had surely forgotten about the one event for which that suggestion seems ridiculous: the Christmas party.

Either that or she was attending far classier Christmas parties than the ones we go to, with tinsel wrapped around every free-standing object and even the most handsome men rendered ridiculous by a Christmas jumper (the best selection is at funkychristmasjumpers.com).

The Christmas party is the one event in the social calendar for which there are no rules – or, if there are rules, they go something like: more, more, more.

Of course, rules are made to be broken, so if you are the type of person who likes nothing more than wearing a black tuxedo jacket with a pair of black cigarette pants and a red lip, go right ahead.

But for those of us who enjoy a bit of peacocking, Christmas is the time to get strutting.

Go for broke with colour and silhouette: the bigger the skirt, the closer you’ll resemble the Christmas tree, which is no bad thing.

Obvious cues, which are usually to be avoided, can now be embraced: Fran & Jane’s bottle-green sparkler, for example, is a festive choice (with some handy stomach-based draping) while Dice Kayek’s mini-skirt, with its oversized bow, is a gift and a half.

While you can forget most rules on this most festive of nights, there are a few things you should definitely avoid:

Cleavage:

This is, after all, an extension of the office, and cleavage is not for the office. Anyone who begs to differ should report immediately to HR.

Mesh panels:

I would quite like to ban mesh panels in general, but I’ll settle for advising you give them a wide berth at the Christmas party. Ask yourself: do you really want your boss to have memorised the freckle pattern of your rib cage?

Anything that requires you to leave your underwear at home:

Do not be fooled by the elaborate decorations and feeling of mirth: this is still a work environment, and we, in civilised society, wear pants to work, unlike some (ahem, Gwyneth Paltrow).

Sexy costumes:

Although, if you’re leaning in the direction of wearing a sexy Santa, elf or reindeer get-up, perhaps you should just do what you feel is right. After all, there are plenty of other people who would love your job when you’ve been given the brush-off.