Often the last, but most important thing to arrange before you travel, is travel insurance. If you travel overseas from Australia, OR if you are coming inbound to Australia, it would be unwise not to take out some form of insurance cover.
As soon as you have booked any part of your planned holiday, you should always book insurance next, as you just don’t know what is around the corner.
Not all insurance is the same: look for adequate cancellation cover, repatriation, excesses, lost money, property or documents, so that you are not left high and dry in a strange land. Remember, if you can’t afford travel insurance, you can’t afford to travel!