Speaking to an audience of about 200, including party supporters, at Victoria University, he said it would mean a focus on what was needed "and not sweat the small stuff".
"There are lots of very worthy but small issues that could easily distract us from the already Herculean task in front of us."
It was a message to the party faithful to prepare to swallow some dead rats - early on in the new government there was some internal friction after the party had to agree to support NZ First's Waka Jumping Bill, a concept it was opposed to. It has also effectively had to put progress on the Kermadec Ocean Sanctuary on ice at NZ First's behest.
But Shaw also sent a veiled message to NZ First that it would need the Greens' support as much as the Greens would need NZ First's.
He said it was necessary to learn "the give and take" of coalition government as well as persuading NZ First and Labour of the merits of collaboration. "We are not the Government alone, but no party is."
Shaw also cautioned supporters against taking an "us and them" attitude to political rivals.
"We have to include everyone, including those who - at least for the moment - disagree with us.
"I know there will be many on our side who, with justification, will say 'they had their time, it's our turn now and time to look after our own as they looked after theirs'. That is understandable and tempting. But it is not sustainable."
He said a wide buy-in would be needed if the changes were to survive successive governments. He got the biggest round of applause when he said the Greens would need to be in Government after 2020 to bed in its reforms - but he also pointed out that would not always be the case.
Shaw ran through some of the proposed changes the Green Party would be leading, including the Zero Carbon Act - "the most significant piece of legislation to protect our environment in the history of New Zealand."
He said Julie Anne Genter and Transport Minister Phil Twyford would also release a new policy statement on transport, "which will radically shift investment in our transport systems".
He said New Zealand had long been a "laboratory of new thinking", pointing to womens' suffrage, and the economic reforms of the 1980s and 1990s, which were "now crumbling".
He believed the Greens in the new government could spearhead a reshaping of that economy, including by adding environmental factors in the measures of economic growth.
Shaw was introduced by new Green MP Chloe Swarbrick and the Green MPs who are now ministers also spoke briefly after his speech - Eugenie Sage and Genter.
Genter spoke of the radical changes to transport she was pushing for, including making it "safe for children to walk and cycle to school".
The party is expected to start the process of electing a female co-leader to replace Metiria Turei in the next couple of months but so far only Marama Davidson has clearly indicated she will contest it.
