And just like at school camp, there are certain expectations of reciprocity.

Mel, 29, recalls a recent wedding where one friend who wasn't asked to be bridesmaid called up the bride and threatened not to attend unless she was instated. "I can understand feeling hurt, but to go to the extent where you confront the bride is a bit extreme," says Mel.

The best thing to do in this situation is to take a "chill pill", says Smaggle.com blogger and three-time bridesmaid Carly Jacobs, who recently released a podcast guiding would-be bridesmaids. "There are so many circumstances in which you may or may not be asked [to be a bridesmaid]. It might be due to a family tradition or financial reasons. Most of the time, it's not a personal insult."

Perfectly pretty: getting dressed

The days of brides decking out their friends in hideous dresses so as not to be outshone are long gone, according to Sydney celebrant Patty Kikos.

The problem is that style often comes with a rather hefty price tag, as Annie discovers in Bridesmaids. Not to mention the fact that different people have different opinions on what looks beautiful. Says Mel, "My experience has always been that you say, 'I'll buy my dress if I get to help pick it' - and you end up paying $600 for a dress you hate."

Sometimes, it's a matter of taking into account different body types - or not taking them into account. Sophie, 28, recalls a dress-shopping expedition that ended in tears. "They were trying to squeeze our friend who was a size 14 into a size 8."

Dedication to getting everyone looking their best can make shopping an endless ordeal for some bridal parties - Sophie's friend set aside two full days for shoes alone. And then there's grooming.

"We were given a list of things to do," says Sophie. "We had to wash our hair the day before, and get our nails painted the week before in a neutral colour. We were allowed to wear whatever perfume we wanted, though."

All systems go: the planning committee

The scale of some modern weddings means that no couple could pull one off without help, so bridal parties can become amateur wedding planners. In Bridesmaids, the big day includes fireworks, a moat and a surprise performance by '90s girl band Wilson Phillips - thanks in no small part to the efforts of Helen, who "wants everything to be perfect and flourishes on these occasions", Byrne explains.

Lisa, 27, has observed similar feats of party planning among her friends and family. When her cousin married last year, the big day incorporated fireworks, Vespa scooters and a floor show. It also required the bridal party spend every weekend for the better part of a year at her house getting organised.

The view that bridesmaids are, well, the bride's maids is not uncommon within the wedding industry. As a "perpetual bridesmaid", Jacobs has seen four years "go completely towards [her friends'] weddings" - and she's okay with that. "I've known my best friend for 20 years," she says. "If one of those years is all about her wedding, that's fine."

At its best, this kind of high-level involvement can even be a bonding experience. May, 30, happily recalls sitting around making invitations over beers in the lead-up to one of her friends' weddings.

The key is to keep it manageable, and to only ask for as much as people want to give. "People want to be able to complain with you about how ridiculous the whole process is," says Meg Keene, editor of the website A Practical Wedding.

It's party time: the events

If there's one wedding-related event guests anticipate more than any other, it's the hens' night, with its boozy atmosphere, low level of formality and penis-shaped straws. But these days, there are more pre-wedding events: the engagement party, the kitchen tea and the rehearsal dinner. And they're just the basics.

From the bride's perspective, this just seems like a good opportunity to hang out with friends and family. For the rest of her wedding party, most already juggling work, family and other commitments, they can turn into burdens - especially when it gets costly. In Bridesmaids, Annie and Helen battle over whether to hold the hens' do at the bride's low-key family farm or glitzy Las Vegas. And when Helen hosts the bridal shower, she goes all-out, with a chocolate fountain and a pet puppy for every guest to take home.

Mel thinks one reason bridesmaids' roles are growing is because the old wedding duties aren't relevant any more. "You don't do your friend's hair and make-up, you have a professional. You don't need to tell them what sex is like, and you're not advertising yourself as an eligible woman of marriageable age. Instead, you're cast as a supporting actor in someone else's princess story."

Cracking it: the pressure

Few brides start out wanting five pre-wedding events or asking their friends to wear a matching shade of spray tan, says bridesmaid veteran Mel. Rather "it's a slow creep", a product of months and months of pressure. "It comes at them from all sides," she adds. "Some people walk into a shop to buy a pair of shoes and walk out with a pair of earrings. Others go to wedding expos to find a dress and come back with a particular part of the world they want their food and flowers to be from. Before they know it, they're under a lot of stress and financial pressure."

"Weddings are just an emotional hothouse," says Dorothy Polka, editor of the Australian wedding blog Polka Dot Bride. "Everything that is stressful in your life and your relationships tends to escalate. And while I don't agree with it, everyone is telling you that it's your day and everything should be your way." It's often the women who started planning their weddings in primary school who are easiest to deal with - at least the bridesmaids know what they're in for.

Other times, as in Bridesmaids, it's someone in the bridal party who cracks. Jacobs recalls a story of a bridesmaid so intent on having her hair done first on the wedding day she turned up to the salon early and physically attacked the stylist.

Doing it better: the counter-trends

Being a bridesmaid isn't all bad, however, and the friendship with the bride usually survives. Most people say they'd do it again. "On the day we all had a ball," says Sophie. "Most of the stress was gone, and we all got to hang out as friends." Kikos agrees, saying, "In my line of work, I don't see many bridezillas." What she does see are couples working hard to make sure their friends have a good time.

Kikos has also observed a trend towards couples rewriting tradition, with an increase in mixed-gender wedding parties and couples walking down the aisle together instead of the woman being "given away". Grooms are playing a bigger role in planning, too - a trend that bodes well for overworked bridesmaids.

"Even though the event itself can seem odd, it is nice to spend time with your close friends," says Mel. "The reality is that even if the couple have been cohabiting for several years, there is an aspect of your friendship that really changes when someone gets into a serious relationship. We've spent 10 years talking about boys. Now you're going to be talking about the same boy, and I'm going to be talking about the bartender at your wedding."

And when you get down to it, that's what being a bridesmaid is all about: standing beside your friend as they go through a major life transition. Forget the parties and ill-fitting dresses, says Keene: "What being a bridesmaid is really about is emotionally taking care of the bride on her wedding day. We've just attached all this extra stuff to it."

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