For a year now I have had a system that I have managed to follow (somewhat). I go to the grocery-store only once a week, and then I buy everything I need for that week. I make a list, and buy only that. And I might make a trip on the weekend for some snacks and soda. Works pretty well. But it is a transition, and something I have had to really practice. It doesn’t matter if you mess up every now and then. Building better spending-habits is not an all-or-nothing process.