Fly to French Polynesia
The best way to reach French Polynesia is by flying to Faa'a International Airport, Tahiti. From there, you can find connecting flights to other islands in French Polynesia.
All flights from Australia to Pape’ete are via Auckland. In Auckland, Qantas Airways flights connect with Air Tahiti Nui. Fares increase considerably in the high season (June to September and over Christmas). From Sydney expect to pay about A$1050/1500 for a return trip in the low/high season with either Qantas or Air New Zealand.
If you want to know how to get there from other parts of the world, find out here.
Cruise to French Polynesia
You can travel by cruise ship to French Polynesia. This can be a lengthy trip but if you have the time and don't get sea-sick, then why not. A quick google search can take you to multiple companies offering cruises to French Polynesia.