How I save money is going Costco with my BF or mum. We share washing powder/toilet paper wipes etc. so then we split the bill. That's how I buy in bulk other wise I would never be able to afford it. Also Vegemite etc there works out cheaper for example 1kg is $12 I think.
We eat lots of leftovers (left over night) ha!! My worst thing is buying food/drink out!!