England head coach Jess Thirlby said her side were "schooled" as they slumped to a 69-49 loss to Australia in the final of the Nations Cup at Leeds' First Direct Arena.
The Diamonds stretched a 10-goal lead by half time and a flat England were unable to chase it down.
Australia continue to set the precedent for world netball, having won every trophy they have contested since 2022.
"We were a bit naive and we didn't stick to the game plan," said Thirlby.
"We let ourselves down with the number of errors in patches. I will never question effort. I think we have some mental battles we need to bring to finals netball, and we're only going to get better at that the more finals that we're in."
It was another agonising final defeat at the hands of the world number ones for the Roses, whose inexperience in finals was exposed by a team who know all too well how to win titles.
England beat Australia in the preliminary stages at last year's World Cup and fell short by just two goals in London last weekend, but on both occasions, went on to lose the final.
"We're disappointed we weren't able to bring the things we've taken from each performance and implement them in the game early enough and for sustained periods," Thirlby told BBC Sport.
"Worse than that, we were schooled at times. The game management needs addressing."
The Roses were nervy at the start as Australia established a seven-goal lead but closed the gap to four by the end of the first quarter.
Defensively, the Roses struggled and Thirlby quickly made changes, bringing on Ellie Rattu, who impressed in the win over New Zealand on Saturday, and shifting Funmi Fadoju to her favoured goal defence position.
But the Australian pressure continued as Courtney Bruce, arguably the world's best defender, had the better of Sasha Glasgow, while Sophie Garbin and Sophie Dwyer punished mistakes with goals, missing just four shots between them all match.
Boos rang around the arena each time a decision went against the Roses and cheers erupted for every penalty they were awarded, but by the half-time break the mood was flat.
Having roared the Roses on to court before the match, the crowd greeted the half-time buzzer with total silence as Garbin scored to stretch the Diamonds' lead to 10.
More changes came in the third quarter as Thirlby trialled numerous combinations. But none had the desired effect as England scored just three goals to Australia's seven inside four third-quarter minutes.
Natalie Metcalf put her head in her hands as Jamie-Lee Price intercepted a wayward pass and the errors kept coming as a dominant Diamonds took a monumental 18-goal lead into the final period.
The final quarter brought much of the same as a frustrated Eleanor Cardwell tried to galvanise her side but the damage had already been done as Australia head coach Stacey Marinkovich made changes at will and England looked shot.
Earlier on Sunday, New Zealand beat Uganda 62-57 in the third-place play-off match.
'We're putting ourselves in the mix'
The Roses showed immense progress and determination to reach the Nations Cup final, beating world number two side New Zealand in the semi.
But their difficulties spiralled once Australia began to build a lead, and they fell short against netball's dominant force once again.
Of the 85 times the two nations have met, the Diamonds have won 75, with one draw and nine England victories, two of those coming since pipping Australia to Commonwealth gold in 2018.
But Thirlby said she can take positives from the fact her side are reaching finals after years of consistent appearances in third-place play-off matches.
"We're putting ourselves in the mix now - that used to be for others and we were always the bridesmaid," she said.
"We've made huge strides on and away from the court. Mentally I think we're more robust than we've ever been. We keep finding a way to get to finals. We have to keep doing that to find a way to win them. That's just where we are and we have to accept that right now."
The Nations Cup marks the end of the international season and players now head off to their respective domestic teams, with the Super League beginning on 17 February.
"I think it's been the best six months post-World Cup of any England team; there's no doubt about that," said Thirlby.
"These girls need to get back to domestic competitions now and stand out and raise the level for others too. Ultimately we need the quality across everything to go up. That will put us in a better position when we come up against these teams again."