The annual Met Gala, held every May and this year on May 2, sees the world's most important celebrities, models, socialites and designers descend on New York's Metropolitan Museum of Art for what has become known as the Oscars of the fashion world. The careful negotiations involved in dressing VIPs for the red carpet are notorious (Wintour famously once vetoed Madonna's outfit because it bared her nipples), but the exact nature of the meticulous behind-the-scenes preparations has been a mystery.

Until now. A film directed by Andrew Rossi, The First Monday in May, which opens in Australia on May 12, will show for the first time how Wintour curates everything from the table-and-chair configurations to the aesthetic of the canapes – even rolling up her Chanel sleeves to pick up litter mere minutes before the ball starts.

Wintour is as exacting about the food as she is her staff's commitment to the $A17 million party, according to the New York Post, which spoke to caterers and organisers familiar with the Met Gala. She's banished bruschetta from the menu for fear of crumbs landing on a dress. Meanwhile, Stephanie Winston Wolkoff, head of events at Vogue until 2009, says she split the stitches from her caesarean section after having to return to work soon after the birth of her daughter to finish the frenzied preparations.

But before you presume finickity food requests and United Nations levels of celebrity diplomacy are confined to the Met Gala alone, think again. Manic attention to detail and perfectionist hysteria are common practice at most big fashion events.

Bertie de Rougemont, founder of Cellar Society, which catered for Kate Moss's wedding, says that creating the perfect canape is a military-style operation. "If offerings look like they've been titillated with tweezers for 30 minutes, it's usually because they have been," he says. "If I spot one elegant woman after another refusing something then I sense danger."

During the planning, de Rougemont works with his client to create an on-brand menu. "One fashion retailer wanted something really boyish, so we settled on cheese toasties, but then went through countless rounds of road-testing to make sure no bits were going to fall out," he says.

After food, seating plans cause the most angst. "Celebrity agents will be on the phone negotiating who their client will be sat next to. They're all aware of being part of the 'money shot' – the image which will be beamed around in the news and on social media," says one fashion publicist, who has been known to survive on just a couple of hours' sleep perfecting seating charts so that nobody is put next to their husband's mistress or hated former colleague.

If there is one person qualified to instruct on party etiquette, it is Diane von Furstenberg. The fashion designer's fashion party experience extends from Venetian costume balls, where she danced until dawn alongside Liz Taylor and Richard Burton, to extravaganzas at the famed New York nightclub Studio 54. Her simple rule for the ultimate party is: "A great host behaves as a guest, and a great guest acts like a host." The biggest mistake, she adds, is to never stop planning – which is easy to do when, for so many working in fashion, image is everything.

Telegraph, London

The Met Gala is on May 2. The First Monday in May opens in Australian cinemas on May 12.

How to throw an Anna Wintour-approved party

DON'T use paper napkins; they look cheap. Opt for linen instead.

DO serve ice-cream. In a sandwich. It's messy but it's also fashion's most in-demand party food right now.

DON'T go anywhere near red wine. The possibility of stained teeth, carpets and dresses is too risky.

DO have raw food. As long as it's not steak tartare. Shallots are notorious for causing bad breath.

DON'T mention mini-burgers. They're impossible to eat and don't look chic, so they're off the menu.

DO serve bowls of potato chips. But only if your party is held somewhere where "gentrification" is a buzzword.