Meal plans have been a godsend here. Plan everything for the week, all meals and snacks (sounds like lots of work but gets easier the more you do it). Go through your cupboards, write a list of what you need and stick to it. I try not to go to the shops between grocery shops. And check out discount shops (the $2 ones) and Big W for thing slike toilet paper, shampoo, conditioner, washing powder etc. Heaps cheaper.