The Christmas party season gets a bad press on the style pages, and not without good reason. As a religious festival, as a commercial opportunity or as a chance to drink one’s own body weight in spiced wine while treating the boss to a few pointed “home truths” about the way the business is run, clearly the holiday period has much to recommend it. But it’s hardly what you’d call a triumph of good taste.

All that tacky tinsel, all those gaudy baubles. All that forest green and fire-engine red. All those simpering fairy-lights and despairing trees. All that cheap sentimentality and expensive kitsch. And, oh, my dears, the noise! The people! And the menswear!

It’s not just the jolly festive jumpers (although it is those, too — the scene from Bridget Jones in which poor Colin Firth is forced into a knitted reindeer sweater continues to haunt the dreams of men’s style watchers 14 years on). It’s not even the sight of normally mild-mannered middle managers leading conga lines through the office while wearing novelty Santa hats.

Because, while regrettable, these are by no means the most dispiriting seasonal sartorial mishaps. That prize goes to the Christmas partygoer who believes that in order to signal to colleagues and clients and even close friends that he has got his Xmas funk on, all he must do is remove his tie and undo the top button of his shirt and, well, that’s it. He removes his tie. Like David Cameron and chums at a G7 photo-call. The shame of it is that it is perfectly possible to get into the swing of the season while remaining dapper and debonair.

First, the office party. I’m not going to use the most fearful phrase in the style lexicon: smart-casual. However, dressing as you would for a board meeting — grey flannel suit, crisp white poplin shirt, navy silk tie and polished brogues — seems somewhat de trop. As does turning up for work dressed as Will Ferrell in Elf. It’s meant to be fun, not career-endangering. So a happy medium must be negotiated between sartorial teetotalism and the style equivalent of binge-drinking.

The good news is that contemporary men’s fashion has made things easier for partygoers aiming for relaxed elegance. After a number of years in which a buttoned-up aesthetic held sway — the Mad Men look — men’s tailoring has taken a more relaxed turn. Cuts are looser, fabrics softer. And the idea of the “broken suit” — what women, less melodramatically, call “separates” — has come to the fore: grey trousers with a blue jacket, or perhaps a subtle difference in shade or texture between top and bottom. Italian labels, in particular, have perfected this. Giorgio Armani, Ermenegildo Zegna and Brunello Cucinelli all find the sweet spot between business and pleasure, catering to men who wish to look smart but not stuffy.

Start with the blazer. Armani is king of the unstructured jacket. His are made in the softest textures with innovative, tactile fabrics; flattering, unshowy and a pleasure to wear. And you don’t look like you’re about to deliver a PowerPoint presentation when you make a move towards the dance floor. (Easy there, tiger.)

Another tip: try to find something you wouldn’t wear to work on a wet Wednesday in March. If you typically wear a single-breasted jacket, go double. Are all your trousers flat-fronted? Then try a single pleat. Zegna’s are cut looser and flappier than you might be used to, and this is a good thing.

Wear a blue shirt instead of white, and not in a loud executive check. Think about your comfort: it gets hot at parties, so maybe a super lightweight cotton from Emma Willis or Turnbull & Asser. Buy a knitted silk tie; Drake’s are my favourite. And ditch the lace-ups in favour of a softer loafer, from Tod’s or Berluti.

For formal client lunches, you will still want to wear a suit. Prada will make you look slick but not ceremonial. Savile Row tailor Kilgour does sharp, off-the-peg suits with modern details — thin lapels, flapless pockets. Something more conservative? A suit from Thom Sweeney’s ready-to-wear collection at Mr Porter. Alternatively, corduroy has been reanimated. My own is a dark navy needlecord from Hackett, and there’s a bottle-green Burberry number that I covet.

Don’t mess with black tie. Tom Ford is the reigning ruler of luxurious men’s eveningwear, and you might also consider Gieves & Hawkes and Richard James (below right), both of whom cut a mean dinner jacket. And get it tailored, so you don’t look like a waiter.

Then there’s the day itself, the culmination of all that carousing. It’s not the 1950s, you’re not Bing Crosby, and no one expects you to wear a dickie bow. True, it’s pleasant to open your presents in your jimjams (Derek Rose, please) but later on you’ll want to put on something knitted. The winner of the Tasteful Christmas Jumper award this year is Gucci’s sumptuous Fair Isle sweater. My own December 25 standby is a Ralph Lauren Polo cashmere cable-knit. If yours is a traditional family Christmas, you can’t go wrong with Ralph.

Naturally, exceptions to all these rules are made for a certain apple-cheeked old fellow with a snow-white beard and a sleigh. And no man, no matter how particular in his dress, should attempt to make it through to Boxing Day without at least once settling a flimsy paper party hat on his head. It is Christmas, after all.