Another Australian here too.

Yes, contacting your MP and senators can be very useful, including for federal stuff.

It's harder to actually get meetings with Federal members (they spend a lot of time in Canberra) but still worth trying.

Also it is very effective to vote for independent senators. You need to pay careful attention to make sure they aren't secretly insane but senators like David Pocock and Jacqui Lambie are very effective (Lambie seems crazy sometimes but she is surprisingly willing to change her mind on issues).