Every bottom line set by NZ First leader Winston Peters through the election campaign would have been on the minds of the other leaders who knew there was a good chance he'd hold the balance of power.

National leader Bill English and Labour's Jacinda Ardern will now be looking at those key policies to determine what, if anything, they'd be happy to adopt in order to form government.

To Peters the most important issues have ranged from not taxing farmers for water, manned re-entry into Pike River and a reduction in immigration.

Now that the campaign is over and it's confirmed he's the kingmaker, he's keeping tight-lipped on what exactly are his most important priorities.

"It would be very foolish to tell you, wouldn't it?

"Negotiating is about getting all you possibly can for the people that voted for you and that means you've got to be smart, and clever, and determined and resolute and the last thing you do is start playing your cards before you get to the table."

Despite English suggesting on election night that he wanted to get started on negotiations "reasonably quickly" the process will go at the pace Peters determines.

He's not in a rush. While he declared on Saturday night he held the most important cards, the full deck won't be revealed until October 7 when the special votes, including the results from overseas voters, are released.

In 2014 those votes took one seat off National and gave it to the Greens. Early predictions this year have suggested National could lose two seats, with traditionally left-leaning votes giving an extra seat each to Labour and the Green Party.

Once that's determined the real negotiations are expected to begin.

Ministerial positions are not off the table, but the question now is what Peters might want. He's been deputy prime minister twice before, working with National under Jim Bolger and Jenny Shipley and Labour under Helen Clark.

But at 72 Peters says he's "been there and done that", apparently not keen for a third go. He's also been foreign minister and treasurer, the latter being a position created for him.

But he said he'd put principles before power.

"I'm a person that walked out twice from ministerial positions, in fact the second most important person in this country, on a matter of principles," he said.

Other MPs could also be in line for ministerial or associate positions, including deputy leader Ron Mark, Tracey Martin, Fletcher Tabuteau and Darroch Ball.