Preferential voting is your friend! The idea that The Greens can’t do much is a myth peddled by Labor for their personal gain. Greens do best in the Senate though admittedly some electorates it’s incredibly difficult to shift the incumbent (like Curtin which has been solidly Liberal for almost all of its near 70 year history). Preferential voting is a wonderful system where you can put Greens 1st and then Labor 2nd and if Greens don’t win then your vote goes towards Labor. BUT! The system also works to give funds towards parties that gain a certain amount of votes so that they can use it for the next election. So even if Greens don’t get in your vote can count towards them being given more money to fight for seats that are easier for them to obtain. So don’t throw away your belief in a party simply because you don’t think they’ll win.