Define "vote for".
If you are in an election with mandatory preferential voting your last 3 places should be greens coal/lnp/whatever and labor. If you put them higher than that you ARE voting for them.
If you are lucky to be able to vote partial preferential then you should give them no vote at all. This is why they force us to mark every box, it increases the chance their bunny will get up.
Since I was 18 I've voted independents and minor parties. It doesn't matter which one you pick either way you put a scare into the majors. I have on a few occasions put a 0 in every box. It kills me to do it, voting is a duty, but when there are only 3 boxes I can't bring myself to vote for any of them. I hate this situation so much I'm thinking of getting on the paper for teh next state election, just so _I_ have someone to vote for (anyone who votes for me is an idiot).