Thankfully Chicken Nation have produced a useful cartoon to explain how it actually works and why you might want to preference a non lizard before making your final lizard based decision at the end of your preferences.
You only get one vote every three years. If you muff the ballot you can ask for another one. So take the damn time and don’t fret about “wasted” votes.
UPDATE: Meanwhile GetUp are explaining the Senate Game of Thrones style: