If you are seriously contemplating long-distance travel and your main destination is Australia, there is one way of going about booking a holiday that will work out to be cheaper than other options, but crucially, will enable you to take in a number of other places en route.
This is the concept of booking an around the world airfare. This often works out to be very good value for money, rather than booking many separate flights. The main rule here is that you continue to travel around the world in the same direction: for example, you will usually have to keep travelling east with such tickets from the UK.
So, you can break-up the long journey to Australia with a stopover in destinations such as Singapore, Hong Kong or Bangkok. This makes the holiday far more interesting and the journey will be so much more comfortable.
Once in Australia, one thing that I did on this fare, was to book to arrive in Perth and spend some time there, and then travel east to Sydney. This is all included in the same fare and allows you to see both coasts of this immense country.
Then, you may even travel on to New Zealand for a few days - Auckland is always very popular! After which, you take the long trek across the Pacific Ocean. I found this one to be the worst, so you may want to head to a really interesting place at the end. Los Angeles is very popular - if a little boring. You may prefer somewhere like Hawaii, or how about Vancouver - which is where I went?