The 41-year-old Sutton mum and public servant isn't leaving anything to chance and has spent many hours discussing her final farewell with her family.

It's up there with "the birds and the bees" and "talking about periods" in terms of uncomfortable conversations, she says, but it's a conversation she's pushing every Canberra family to have.

"It's about sitting at the dinner table, or even when you're driving in the car with your kids and your husband or your sister or brother and asking a single question," she Ms Greenhalgh says.

"Like, 'have you ever thought about what you might like when you die? What colour flowers would you like? Do you want a cardboard coffin? Do you want a wooden coffin? Do you want bling? Do you want rainbows and unicorns?'

"I know it's confronting, but if you're clear on what you want, it just makes it so much easier for those people having to arrange everything in your absence."

Sadly, Melanie has "a high level of experience" in arranging funerals.

In 2009, she lost her mother Lyn and her sister Megan within six months of each other. Lyn lost a three year battle with breast cancer, while Megan, aged just 24 at the time, died suddenly of a pulmonary embolism - a blood clot in the lung - at home.

The experiences of arranging both funerals couldn't have been more different.

"With mum, we had time to have the conversations around what she wanted, and we just designed the most beautiful experience," she says.

"We had her wake at the the Botanic Gardens because she just loved the gardens and loved the idea that during her wake the kids could be exploring and searching for fairies in the rainforest.

"With Megan, it was the opposite. She died so suddenly and was just so young that we had never had those frank conversations. I didn't even know if she wanted to be buried or cremated.

"I had to just go with my gut on everything, and honestly, sometimes some of the decisions I made about her funeral weigh heavily on me."

Mrs Greenhalgh, who adopted Megan's children Jackson and Jesse, aged four and 18 months when their mother died, gave an emotional talk on grieving at TEDX Canberra last year.

And she has her funeral planned to a tee.

There'll be plenty of Paul Kelly and Crowded House, but if curried egg sandwiches are served she'll "be furious". She has been very explicit with her friends on which row they're allowed to sit in.

"Clearly I have sense of humour about it all but it just helps with having that awkward conversation."

She also loves that you can now buy coffins at Costco.

"It brings the conversation around death into the mainstream," she said.

"It's like you can get bulk toilet paper, soft drink, cleaning products - oh, and a coffin. It makes death just another part of life, which it is."

Costco Canberra warehouse manager Sai Muluk said the coffins at Costco had attracted a lot of attention since being stocked in June of last year.

Seventeen Canberrans have purchased coffins since they became available at Costco, with "The Richmond" - a faux mahogany coffin with silver handles which retails for $679.99 - proving the most popular choice in the ACT.

"We get phone calls every other day from people wanting to know if we really sell coffins," Mr Muluk said.