After waiting days for Border Protection to provide a process for GST collection for importers - they gave me a link to the ATO website. So when you ask the ATO how its done, they give you the link to the Border Protection site.
The only way is from what I've gathered ;
If you have paid for your import prior to 1st July, even AFTER your shipment arrives, it will be cleared - Fedex and USPS as examples.
If you have paid after 1st July, your goose is cooked. You will be required to pay GST AND DUTY 5% of the total shipment. You MAY have pay admin and clearance fees.

If your purchase is from eBay - non Aussie - the GST component is already added in checkout. If the shipper is eBay Global, your package will be cleared as per normal as you have paid GST. No Duty is calculated - from what I can work out.
If you are buying or selling from Forums and Facebooks groups, you will be targeted. Whatever that means - by the ATO.
RTBB / APR is now registered for GST - so we can claim GST credits etc etc.