Asklemmy

Cutting down on alcohol. Due to Australian tax, it's actually pretty expensive (except cheap wine). Beers at lunch add up.

Pirating media

Buying a large set of 500 mL plastic takeaway boxes with lids (Chinese takeout boxes). They're more useful than just poverty Tupperware, you can use them for storing lots of things, as small mixing bowls, etc.

Buying spices in bulk. There's a store here where you bring your own jars and stuff, all the cumin is loose and you just pay for product weight (which is way cheaper than mainstream supermarkets).

Asian grocers. Everything is generally cheaper, and they sell these large jars of minced garlic with big chunks of garlic (rather than the puree from woolworths).

Generally, the more interesting yet low effort you can make your cooking, the less you'll feel the need to eat out or splurge on "reward" meals. Asian food can be very good for that (east asian, south asian, middle east), and you'll impress your white friends.

Canned and frozen versions of vegetables, instead of fresh. If you're making a stew or curry, it doesn't really matter. Also, frozen broccoli is more floret (the tree bits you pretend to be a dinosaur at) by weight.

Just steal stuff. Do it irregularly, and always be a polite smiling face to service staff. Bring your own bags and hide your stolen produce under the bags. Leave the bags in the trolley and fill up stuff you buy on top of them.

Service what debts you can.

Really, the biggest costs tend to be emergency vehicle servicing, hospitalisations, and rent. Any way to reduce those (sharehousing, having friends that can do those sorts of work, spreading the work out amongst the community) will go way further than a lot of things I've just listed. Community is hard to find though