Liberal if I lived in a swing riding, One Nation otherwise.
Australia has compulsory preferences, so you can put One Nation first and the Liberals second, and your vote would still go to the Liberals.
For the House: Labor or Greens depending on the local candidates; although always preferencing Labor over the coalition parties. If there was a more left-wing independent or minor party candidate standing then I might throw them my first preference to help them retain their deposit since that's probably very helpful for some of the smaller parties
For the senate with the new voting system I might chuck a preference or two to more left-wing minor parties before going Greens/Labor for the same reason; although perhaps that's less likely for the Upper House because preference order is a lot more important for STV elections than it is for AV; even in Australia's weird version of STV.
I thought that the Democrats had died out? They certainly had their place as the third party with the balance of power in the Senate taken by the Greens...
Yes, the Democrats are officially dead, they were de-registered by the AEC last year for not showing they had at least 500 members. Most Democrats became members of the Greens, and the Greens basically took a lot of their voters in the 2000s.