When I found out that the eligible parties get $3.293 of my money (taxpayer's money) per first preference vote, I decided to vote informal in the House of Reps. I live in a very safe Labor seat, so I figured my vote was worthless anyway. That said, my preferred Senate candidate needed every vote they could get, so I did vote formal in the Senate.
If you want to have fun with your ballot paper but still make a formal vote, you can write whatever you want on the paper provided the boxes are clearly numbered. You can add an extra box for Kermit the Frog with an extra '1' in it and still be formal.
