Now costuming is considered one of the most important characters of a show. And nowhere is the style of the characters more important than in period dramas like Australia's little series that could, A Place to Call Home.

Noni Hazlehurst is no longer regarded as "Noni from Play School". To some corners of the internet, she's "Elizabeth with the impressive fur stole collection". The evolution of Hazlehurst into Australia's favourite biddy, a role left vacant after Country Practice's Esme Watson left our screens, is partly thanks to the work of costume designer Lisa Meagher.

Meagher has worked on the series since season two and is pleased the plot of the show, a show The Wall Street Journal cited on its best television of 2015 list, meanders through the 1950s.

"It's a beautiful period to work in," she says. "It was a fascinating era for fashion and it's great for TV as once we hit the 1960s we'll lose all silhouettes. It works as everyone had a waist, which is perfect for TV as it's usually shot from the waist up."

The '50s was a popular fashion period that continues to be referenced today. Not a seasonal showcase passes without at least one reference to Christian Dior's New Look. However not a lot is known about post World War II designs from Australia other than our national dress had an abundance of cotton and linen.

A Place to Call Home is a microcosm of Australia's post-war aesthetic as it takes Downton Abbey's upstairs-downstairs premise and contextualises it for local audiences. In each episode viewers are treated to old-money couture and working-class chic. Prior to filming Meagher spends weeks locked away in the State Library of NSW pouring over family files of pastoral titans and, what she calls, "wealthy people's albums", like ragtrade merchant Anthony Hordern.

She then immerses herself in the world of hire emporiums and rummages through racks of clothes and accessories kept by trusted collectors to source each look the scripts require.

Melbourne, overseas and online is where she finds the majority of the wardrobe. "Etsy is getting better and better and better," she says. "Around the time of season three I met a woman in Brunswick who grew up as the ward of the state and has been collecting items since she was 15. She has trunks and trunks of the most extraordinary clothes and is happy for us to loan them as they are of historical significance but we give them a new story."

While A-line skirts, padded shoulders and single-breasted coats are found locally, Meagher looks to the United States for knits and the majority of the suits.

"Twin sets for the women that are the right length are difficult to find in Australia. It's quite specific as that's what keeps the silhouette of that period," she says. "America had a lot of money in the '50s and it shows specifically when it comes to menswear. Menswear is hard to get here, they wore it all out."

Season four sees series favourites like Elizabeth, Sarah (Marta Dusseldorp) and Regina (Jenni Baird) tackling the contrasting social issues occupying Australia's national consciousness in 1954 – communism, the fall out of the Petrov Affair and the wave of liberal change that offered up new social and moral avenues.

Behind-the-scenes work was gruelling for Meagher on set. Eight weeks of wardrobe preparation was needed for the shooting schedule which saw two episodes shot every 15 days.

"A lot of the characters don't wear the same thing more than once and we have even more engagement parties, weddings and tea room scenes so I'm thankful I have a budget and a great team for support."

Elizabeth's blossoming romance with Sir Douglas (Robert Coleby) and Regina's continual pot stirring and addiction issues are highlights for Meagher. Expect to see a lot more florals on the two divas of Ash Park when the series returns on September 11.

"Someone like Regina who is always scheming and plotting, she dresses for every occasion to work it her way. You always have a laugh with that, like when she's trying to be nice, we put her in floral," she said. "There is a specific dress with a ruched collar that she wears when Menzies comes to visit when she is at the height of her morphine addiction. We needed to present her in something that crumbles and slouches like she does physically as the episode progresses," she says.

"However we've really lightened up Elizabeth and moved her into softer colours."

But it was Carolyn (Sara Wiseman) and her journey from free spirit to rape victim and Sarah's mourning period that fired up her imagination.

"Carolyn in season three was always very flamboyant and confident and then there was the rape scene with Sir Richard so then to bring her back without losing her style was interesting. We made her paired back," she adds. "Sarah is still dealing with grief and going through the motions of losing her husband but we are really bringing her back too this season, her life is looking up again."

A Place to Call Home season four airs on Sunday, September 11 at 8.30pm on Showcase.