Last month’s most stylish, from Mr Jason Atherton’s navy blazer to Mr Paul Bettany in wedding-ready lightweight cotton .

Summer is practically upon us, and that can mean only one thing – well, apart from the Olympics, the Queen’s second 90th birthday and people cursing El Niño for even more unseasonal conditions than usual, that is. It’s summer wedding season, which comes with all the attendant dilemmas: how can I look sharp while staying cool? And what’s the best outfit for only subtly upstaging the groom? Thankfully, the men in our best dressed round-up have heard your pleas, because they all brought their tailoring A-games to bear last month. Follow their lead, and you’ll always be a wedding smasher rather than a wedding crasher.

Style is in Mr Francesco Carrozzini’s genes – he’s the son of Italian Vogue editor-in-chief Ms Franca Sozzani – but even so, the photographer and film-maker surpasses himself with this counter-intuitive tailoring masterclass, bringing some Patrick Bateman-esque pinstriped chutzpah to shake up the linened denizens of Beverly Hills. Mr Carrozzini mitigates against 1980s-costume-party cliche by keeping his double-breasted jacket nipped in rather than boxed out, and accessorising with a just-the-right-side-of-slouchy knitted tie and an expression that vies with his grooming regimen for insouciance. All of which lends him the air of a best man who’d be fully prepared to spill any scurrilous, if not serial-murderous, beans.

And what of the real American Psycho, aka Mr Benjamin Walker, who is currently playing Patrick Bateman to striking, sliced-and-diced effect on Broadway? He, too, plumps for double-breasted dynamism at the musical’s opening-night party in a navy number, courtesy of… Well, modesty forbids us from mentioning the provider of this Kingsman ensemble (and, indeed, the whole of the men’s wardrobe for the show), but there’s a heavy hint behind Mr Walker. With a DB, it’s all about the cut. This slim-fit, elongated number accentuates Mr Walker’s enviably sleek physique (though you’d need one, too, if you made your entrance every night in a pair of tighty-whiteys astride a tanning bed). Prospective grooms, take note. This is, quite literally, killer occasionwear.

Mr Jason Atherton, the Michelin-starred major-domo of London’s Pollen Street Social, Berners Tavern and many other acclaimed hostelries, is as celebrated for his tailoring as for his Cornish duck with boulangère potatoes. “I think fashion enhances you as a person,” he says, and here he offers a tasting menu of smart-casual wedding attire. The top-table formality of the navy blazer, monk straps and pocket square is offset by the running-buffet rakishness of the chinos and the amuse bouche of the polka-dot tie. Worth a champagne toast, or even a couple of spoonfuls of Mr Atherton’s champagne and raspberry gratin (sprinkled with tiny mint leaves, natch).

Matrimonial scenarios haven’t always gone swimmingly in Game Of Thrones. You might remember that the nuptials of Edmure Tully and Roslin Frey culminated in a full-blown massacre, rather than everyone kicking their legs up to “Hi Ho Silver Lining”. If anyone risks another wedding in Westeros, male celebrants should follow the lead of Mr Nikolaj Coster-Waldau, aka Jaime Lannister, and opt for a three-piece that’s smart enough to rise to the formal occasion, while boasting enough telling detail – the subtle print, the double-breasted waistcoat, the ticket pocket, the skinny rep tie – to leave even the High Sparrow’s feathers looking a bit, well, drab.

You’d expect a man who recently confessed to having even his swimsuits tailored to step smartly up to the formalwear plate, and Mr Johannes Huebl smashes it, Greek wedding-style, on his latest outing, to Ms Diane von Furstenberg’s awards ceremony, which honours extraordinary women, at the United Nations. Mr Huebl could prove to be the UN’s ultimate goodwill wedding ambassador, should Mr Ban Ki-moon see fit to offer him such a post. With the roped shoulders and cinched fit of his navy DB, not to mention the perky fold of his pocket square, the artfully loosened tie and his note-perfect Blue Steel, he’s really spoiling us.

How do you put together an al fresco ceremony ensemble that’s relaxed enough not to look too buttoned, but is buttoned up enough to distinguish you from someone who’s just wandered in from a beachfront cabana? First, you avoid pineapple prints and comedy Crocs. Second, you follow the example of Mr Greg Unis, the menswear director of Coach, and assemble a bright but cool seasonal palette. The azure blazer teams nicely with the off-white chinos, the russet accents of the knitted tie and loafers make a nice laid-back counterpoint, and even the all-this-attention-for-little-old-me? expression looks genuinely self-effacing rather than some high-fashion humblebrag.

The subtly yet spiritedly patterned double-breasted suit is guaranteed to inject some levity into the summer wedding circuit. Making easy work of its lightweight fit and gossamer heft is Mr Harry Shum Jr. The actor formerly known as Mike Chang off Glee is shortly to be seen in the hotly anticipated kung fu follow-up Crouching Tiger, Hidden Dragon: Sword Of Destiny. We don’t know about that, but Mr Shum Jr shows here that he’s already mastered the Suit Of Sublimity by keeping his DB sharp and close fitting, all the better to pull off a celebratory taiyixuantianfuchen. We know that’s easy for us to say…

Unlike The Vision, the superhero he plays in the Captain America movie, it’s reasonable to assume that Mr Paul Bettany is, sadly, unable to manipulate his density. It’s therefore wise of him to choose a lightweight cotton suit that will keep him cool through all the summer’s possible engagements – weddings, premieres, Avengers re-assembling, Avengers dis-assembling, etc. Mr Bettany’s grey single-breasted number is obviously impeccably cut, but it’s the accessories – the handsomely patina’d Oxfords, the tonal spotted tie, the debonair pocket square – that give it definition. On this evidence, we’d say Mr Bettany is way ahead of The Vision when it comes to the activation of his “evolve” protocols.

The celebrities featured in this story are not associated with and do not endorse MR PORTER or the products shown