Austracantha minax..

...also known as the christmas spider and so called because they are most often seen during December and January.
I thought it might be because they look like teeny (about 8mm in length) Christmas tree baubles.

This is a female looking very glam (the blokes are quite dull in comparison) with her horns and colourful dots and very busy spinning threads between twigs and branches in the increasingly dry bushland.