Make a list of what you where you want to go and the kind of things you want to experience. If you're making last minute travel plans to Australia, you might have to compromise on some things. At least, while you're there, you get to experience as much as you can.
Know a little bit about the country.
There are certain things about Australia that might surprise you if you aren't familiar with it and we're not talking about the local dialect. Cars are left-hand drives and summertime in the U.S. is wintertime in the continent, which means you're more likely to get a heat stroke in December. If you're coming in from the cold, be prepared to shed your clothes.
You might also want to be extra careful about visiting. Just because you're going on a last minute travel to Australia doesn't mean you should remain ignorant about any dangers there. The country, for example, is home to majority of the most poisonous snakes in the world. Even if you're making last minute travel plans, don't forget to bring a sturdy, thick pair of boots.
It will also help if you bring travel accessories and a basic survival kit. There are simply areas in the continent where you need to be extra careful.
Familiarize yourself with your destination.
Last minute travel plans to Australia shouldn't include you getting lost. Contact the local tourism office or book accommodations with local agencies. If you need a car to drive you to and from the airport, have this ready as well. Most travel agencies will be happy to make these arrangements for you.
Ask for extra information prior to the trip or go online and look for travel guides to the areas you plan to visit.