Please tell me you understand that you can direct your own preferences?

This is how you should vote:

1. Put any parties you really like the policies of first
2. Put your least worst major party next (or the lest worst of the two most popular candidates, if you’re not in a Lib/Lab contest)
3. Put the worse major party next
4. Put all the garbage parties after that.

First preferences get reported, so they are a symbolic message to the politicians. But they might also win in some cases, so bonus. If your early preferences get knocked off early, then your preference will flow to who ever you put higher among the last 2 to be knocked off.