1) Rising interest rates due to high economic growth. The cost of borrowing has increased dramatically and has tended to force many Australian's to stop spending.
The RBA has aimed for a soft landing by increasing the basis points over the past few months.
2) Inflated prices especially in real estate (interestingly there has been a reduction in advertisements for those selling houses)
3) Extremely High dollar compared with the US dollar. This can lead to a number of economic problems e.g. decreased tourism and investment and our exports becoming less attractive.