Derek Guy argues that your search for a wedding suit should begin early. “Ideally, many months out – so you can try different styles, see what works and, if it needs a tweak here or taper there, you can give your tailor enough runway to make the good suit great.”

“If you’re buying an off-the-rack suit, take it to your local tailor for some extra tweaks,” agrees Benedict Browne, MR PORTER’s Style Director. “It’s worth the money every time and will convert it from looking like a suit made for any man to a suit made for the man.”

“If you’ve been invited to a wedding, remember that you’re not the main character,” Guy says. “Someone is footing the bill for your meal, the venue and possibly your lodging. At a minimum, they’ve invited you to be part of one of the most important days of their lives. Your clothing should reflect a spirit of gratitude.”

The good news is you’ve probably been told what to wear. But if not, find out. “If your invite spells out a dress code, take it seriously,” Guy says. “If it doesn’t, or if the language is vague, ask.”

“A wedding is one of the few opportunities you’ll have to dress in proper occasionwear,” writes Teo van den Broeke, editor in chief at Esquire UK. “Grab it by the lapels and go for your life in clothes which you feel excited about wearing.”

“If you wear the same suit you wear every day to the office to a wedding, no amount of free prosecco will make your fellow guests unsee the bagginess around your knees and wear around your crotch,” van den Broeke writes.

“For your first black-tie rig, keep it simple,” Guy says, for those new to formal dress. “Start with a black dinner jacket – single- or double-breasted – with peak lapels faced in silk or grosgrain. Pair it with matching formal trousers that have a braid running down the side seam. The shirt should be white, with a pleated or marcella front and a turn-down or wing collar (turn-down is more contemporary and easier to get right). A black bow tie is non-negotiable – hand-tied, not pre-tied.”

“The bow tie should be wide,” says stylist Luke Hodges. “Don’t wear a mean bow tie.”

If the dress code is more forgiving, why not get to grips with the Italian art of breaking up a suit? “Two-piece suits are easy and effective, but there’s more to be said about sporting separates with confidence,” Browne says. “The easy way to do that before advancing to elite levels is by using a neutral-tone trouser, such as off-white, with a blazer in a colour of your choice. It could be a solid brown, or if you’re sauntering around the south of France, a vibrant, summery colour like teal.”

“Make each component – the suit, the shirt, the shoes – the best you can possibly make it with your budget,” Hodges says.

“Today is not about you,” van den Broeke reminds us. “It’s important not to rock up looking like Liberace. This means that as a wedding guest you should avoid wearing any shade relating to white (this includes bone, cream, buff and any other nom de guerre you can think of).”

“If there’s one way to let the bride and groom down on their big day, it’s by wearing tan leather shoes,” Browne says. “Some shades in suede are passable, not but in calf leather. They’re an eyesore and pair awfully with navy, which is the most popular colour worn on wedding days. Stick with dark brown suede or leather for navy, beige, brown and green suits, and black or brown for navy suits.”

Struggling with suit sizing? “If in doubt, go a size up, whatever you’re wearing,” van den Broeke writes. “Suit trousers, in particular, are a repeat offender – they should glide over your thighs, not mummify them. Even when you sit down. Especially when you sit down.”

“Good tailoring shouldn’t hug the body,” Hodges agrees. He says that the trousers should sit on your waist, not your hips, and elegantly skim rather than cling to the legs. “You want a little bit of room for movement. But you also don’t want to be billowing. There shouldn’t be too much material.”

“A linen suit is an obvious choice for a summer beach wedding, particularly in sun-faded shades of tobacco brown, cream, tan, olive and dusty blue,” Guy says. “But not all linen is created equal. A heavier weave will rumple more than it wrinkles, which means you’ll look rakish, not dishevelled, by the end of the ceremony.”

Look like you actually own your suit. “The stitching is put there to stop people who are trying the jacket on before buying it from stuffing their hands into the pockets and ruining the lining,” the writer Chris Elvidge notes. “Once the suit is yours, feel free to take the stitches out.”

We’ve already mentioned not to wear your office suit to a wedding. But there are approaches to the way you dress that can work for both. The fashion psychologist Shakaila Forbes-Bell recently suggested clothing hacks to make a good first impression in a job interview. And a similar principle can apply here.

“A study in the Journal Of Consumer Research found that when people intentionally wore a distinctive pair of shoes that didn’t conform to standard dress codes, such as red sneakers, they were more likely to be perceived as having a ‘greater professional status’ and being more ‘competent’ than those who wear standard shoes,” Forbes-Bell writes.

Obviously, don’t wear red sneakers to a wedding. But having something purposefully just off – like Winston Churchill’s famously slightly askew bow tie – shows that you not only know the rules, but also how to break them.

“Accessories that complement each other, but don’t match exactly, such as a plain tie with a printed pocket square in complementary shades or vice versa,” suggests stylist Eric Down, for those taking it to the next level.

“The secret weapon is a luxe satin shirt with a statement print,” writes John Lockett, formerly of Highsnobiety and GQ. “Pair it with some classic-but-suave trousers – that won’t cause the mother of the bride to flip out – and loafers. You’ll be floating on cloud nine while the stiffs in their rented tuxedos look on with envy.”

“It’s not an exaggeration to say that buying a travel steamer will change your life,” van den Broeke writes. “Not only will it give your clothes a much-needed breath of freshness when you unpack them pre-wedding, it’ll also remove any and all creases, which is an absolute essential as all clothes – even bad ones – look better when they’re properly steamed.”

Now you’re there, it’s time to turn on the charm that already radiates from your attire. Which means mingling.

“Don’t get stuck talking to your bestie or a person who doesn’t know anyone else,” says Malcolm Carfrae, the mastermind behind some of New York’s biggest parties. “Work the room and step in and out of conversations with witty remarks. It’s a great opportunity to meet some impressive people that you might want to get to know better.”

Small talk isn’t everyone’s forte. But there is a cheat code. “Lest we forget that people’s favourite thing to talk about is usually themselves,” writes journalist Annie May Rice. “So, be the guy who asks good questions. If you don’t want the spotlight, you can charmingly divert.”

“Approaching a dance floor can feel overwhelming and scary,” says dance teacher Illana Gambrill. “But with confidence, it’s about faking it till you make it.” She suggests lifting your head – and your gaze – up, keeping your shoulders back and owning the space.

Weddings and alcohol can be a heady mix. But for those swerving the booze, there are benefits that go beyond feeling fine the morning after. For one, you’ll have your faculties about you.

The writer Tom M Ford suggests turning your sobriety into a superpower.

“Think about it. You are probably the only person at the occasion who can operate heavy machinery – so make yourself useful. Can you top up people’s glasses? Can you thank waiting staff in lieu of your mates who are now play fighting? Is there a relatively simple bit of maths relating to an issue with the bar tab that only someone who hasn’t been drinking four different colours of drink over the course of eight hours can solve?”

“An Irish goodbye, a French exit – whatever you want to call it, just say you’re going to the toilet and slip off into the night,” Ford says. “It’s a thrilling, liberating feeling. And absolutely no one will notice.”