Sunday will be a day to remember the 15 lives lost in the attacks and stand in solidarity with the Jewish community, with flags to fly at half mast and buildings to be lit in yellow.
The day will mark one week since two Islamic State-inspired gunmen carried out the attack on a Hanukkah event at Bondi Beach.
Prime Minister Anthony Albanese encouraged Australians to light a candle at 6.47pm "as a quiet act of remembrance" on the day.
"This day is about standing with the Jewish community, wrapping our arms around them and all Australians sharing their grief," he said on Friday.
Lights will beam into the sky above Bondi Pavilion, where thousands of flowers and tributes have been laid since the tragedy.
NSW Premier Chris Minns said planning for a formal, public service for victims and survivors would take several weeks.
"We want as many people there as possible, including those that are currently in hospital or caring for loved ones or are in the process of burying loved ones," he said.
Both leaders have unveiled major anti-gun policies, including what the NSW premier described as the "toughest gun law reforms in the country".
A bill is due to be introduced to state parliament on Monday to cap each licensed gun owner to four firearms and reduce magazine capacities.
Access will be restricted to various long arms including straight, pull, pump-action, button and lever-release weapons.
Public gatherings such as protests will be banned in the state for up to three months after declared terrorism incidents.
"There is a very different world between where we are today and where we were before Sunday ... we have to change," Mr Minns said.
A national gun buyback will also be launched, the largest since the Port Arthur massacre of 1996.
Australia has more than four million licensed guns, up from 2.5 million after the 1997 buyback.
The gun industry has launched a public campaign against the rushed changes, urging meaningful consultation with industry experts and stakeholders.
Federal Labor has also pledged to push hate speech laws as far as constitutionally possible to curb anti-Semitism.
Bondi earlier was the scene of a massive paddle-out as hundreds of surfers paid tribute to those killed in Sunday's horrifying mass shooting, Australia's most deadly since Port Arthur.
"It's just beautiful," Executive Council of Australian Jewry co-chief Alex Ryvchin said of the community-initiated event.
"It's a gorgeous day and you see that scene - I've seen paddle-outs before, but never of that size."
More than 70,000 people from 60 countries have donated in excess of $5.2 million to verified pages for victims and survivors, GoFundMe said.
This includes $2.5 million for Bondi hero Ahmed Al Ahmed, who wrestled a firearm from one of the gunmen before being shot twice in the arm.
Police legacy appeals for two injured officers, including one who could lose his vision permanently, have reached nearly $900,000.
More than 25,000 blood donations have been made since an appeal for help from Lifeblood in the wake of the attack.
About 90,000 appointments have been booked across Australia in a record-breaking show of support.
"What began as a frighteningly large (need for blood) on Sunday night ... has become a full-scale and national operation to accept thousands of generous gifts of blood," Lifeblood spokeswoman Jemma Falkenmire told AAP.
Eleven shooting survivors are still receiving hospital care but none are listed in a critical condition.
The Australian National Imams Council urged preachers to incorporate unity messages in sermons during Friday prayers, highlighting Islam was for "builders of unity and peace".
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