For Mueller, Christmas begins with the annual festive fair at the German Swiss International School when she buys an Advent wreath and other traditional goodies such as stollen which she uses to create a "goodies" table in her apartment.

Next comes the Yule log decorating session with the Red Cross Hospital School at the Royal Hong Kong Yacht Club, where she and her 10-year-old son Alex help out annually.

On December 5, the eve of St Nicholas Day, mother and son follow the German tradition of putting out his shoes on the windowsill in preparation for a visit by St Nicholas.

"If a child has been naughty they will find coal in their shoes, but of course no one is ever that naughty," says Mueller, public relations manager at the yacht club. "Traditionally, they get fruit and nuts but my son usually gets a book or Gummy bears."

When the tree arrives - albeit a little late this year because of a hold-up at US ports - Mueller will decorate it, with Alex adding the special bell ornament which has been in the family for years.

She will also help organise the Christmas tree decorating party at her apartment building, which she initiated a few years ago, sending every resident an invite and special bauble with their flat number painted on.

As the big day gets closer, the traditions come thick and fast and culminate on Christmas Eve with carol singing followed by a Santa hunt when Mueller and her family take to the streets to track down the man in red.

Although she was born in Hong Kong, Mueller says her German parents inspired many of the traditions she still follows today.

"We open our presents on Christmas Eve because my mum brought us up doing that."

However, Mueller has added a few of her own traditions which fit in with her life in Hong Kong. These include the Yule-log making sessions and an annual trip to an art studio, where she has a special silver Christmas tree decoration made with an imprint of Alex's fingerprint.

"I started doing this just after Alex was born. It was something I came up with and thought it would be really cool. I get one done every year and we hang them all on the tree along with some old ornaments I got from my mother," she says.

Keeping up with all these traditions may sound like difficult work, but Mueller believes they play an important role in family life.

"It's nice to have annual traditions. Every family has their own things they do and … they are part of the fabric of childhood and family life.

"We are not religious, but I like Christmas. It's a beautiful celebration, where you decorate your home and spend time with your family."

Other families are also inventing new Christmas rituals while they maintain some traditions. Mueller's Facebook post on traditions was in response to a mother's request for advice on celebrating her second Christmas in Hong Kong away from her home country.

"I want to start our own little family traditions to give my children fond memories of Christmas. Any of you care to share any ideas of what you do with your families?" she said.

Her plea for help attracted more than 70 responses. Some traditions cropped up several times such as carol services, the Christingle Service at St John's Cathedral and buying new pyjamas to wear on Christmas Eve. Other mums shared traditions, which, like Koko's Santa hunt, appeared unique to their own families.

There were also those which had been created to fit in with their Hong Kong life: such as picking up ordered pastries on Christmas Eve, ice-skating at a rink, or taking a ride on the Ngong Ping cable car.

In the true spirit of Christmas, some suggested ways to help people less fortunate. This year, British expat Caroline Crampton is trying to create a new tradition for her children, three-year-old Oscar and baby sister Emilia, which has them choose one of their own toys to donate to a children's charityor orphanage.

"We have been talking about Christmas and Santa coming and it is all about buy, buy, buy. That's not what I want to be teaching Oscar. There has got to be something about giving," Crampton says.

"I think it is important they understand there are people who are not as lucky as they are."

Anthropologist Joseph Bosco is not surprised that people take their traditions so seriously, especially when they are away from their home countries. Nor is he surprised they invent new traditions or adapt them to where they are.

"Many people have Christmas traditions, but for those who are away from their own country or society, they are an important way of holding on to some part of their identities," says Bosco, an associate professor at the Chinese University of Hong Kong.

"These kinds of holiday are ways of marking time. But I think there is an emotional element in addition to wanting to make a connection with home and parents.

"A lot of people have fond memories of Christmas from their own childhood and they want to pass these on to their own children."

There are also parents who want to consciously create good memories for their children. Bosco admits there are Italian traditions his family still observes - even though doing so is not easy in Hong Kong.

"We follow an old Italian tradition of having a seafood dinner on Christmas Eve. It has to be eel, so we have to get an eel every Christmas.

"It is not so easy to find in [a restaurant in] Hong Kong. So I have had to learn how to skin my own eel. I think that shows just how important we think it is to follow our own traditions."