Personal and household effects are able to be imported into Australia duty and tax free if they have been owned and used overseas by a shipper (who holds a valid Australian residency visa) for 12 months prior to shipping. If the goods are new, or are gifted to a consignee, duty and GST will apply. Duty in those cases will generally range between 5-15% (on Customs value) plus 10% GST (on the total of the Customs value plus the duty).
Clients will be required to declare new goods purchased within 12 months prior to shipping on the Customs B534 where they will have the opportunity to state the item, price or estimated price $ and Date of purchase. Australian Customs are usually not particularly interested in items such as clothing but tend to focus on new whitegoods, electrical goods, furniture etc., as well as large quantities of particular items suggesting a commercial level of importation.
Customs Value for HHGPE duty calculations in such cases is based on cost at origin plus freight and transit insurance costs to ship to Australia.