We used to do this, all the time. All the short trips to theshops add up.
My advice would be to sit down once a fortnight, and meal plan. Also, set a budget for groceries you feel is realistic. Then shop forthose ingredients. We tried to make a rule where in a fortnight, we only top up on milk and fresh produce if we need it. We’d very often have a freezer of meat, pantry of food but my partner wanted to make lamb with a red wine reduction, which would require a trip to the shops for more ingredients. Do that a few times a fortnight and it adds up. We eat a lot of organic fruit and veg, free range meat (I’m vego) and good quality fish but I’ve managed to cut our bill way down with just planning. It can be time consuming but I buy my produce at the market, meat and eggs at the butcher/free range shop, staples at Aldi then I’ve only got a small amount to get at woollies/coles. Sometimes nothing. Once a fortnight I also do an afternoon of cooking such as spag bol sauce, vegie dahl, a vegie lasagne, some soup and it all goes in the freezer so on busy nights, we can just pull one out. I also bake snacks once a fortnight and freeze i.e.cookies, slice, muffins and because we have to be careful with additives, we don’t buy many things that come in a packet.
I do a shop once every 2-3 months at costco (or you could atAldi) and spend about $500+ and buy stuff in bulk like washing powder, toiletpaper, household cleaning stuff, anything that can be frozen, etc.
Planning can be a pain (though I now quite enjoy it) but it’s one way to save money.