I am spending three weeks in Thailand in March. I have some family in Perth and am thinking about doing a one-week side trip to Australia.

I have been to Thailand once, and I've never been to Australia before. So I don't really know how to shop for good deals on plane tickets in the region, nor do I have status with any of the airlines in that part of the world.

Can anyone give me some ideas on the best way to get a good deal BKK-PER round trip? Not just who to fly, but also how to book?