A grocery list, that is (but please keep singing!). Don’t scoff- planning at least some of your meals can have a bigger impact than you think. A part of the massive food waste in the US occurs in our refrigerators. Think about it: what food did you just throw out? For me, it was pizza dough (didn’t get to it in time). And pudding (now I know everyone hates butterscotch).
Think it takes too much time to keep track? My list keeps me moving quickly through the store and I usually don’t forget anything, which means fewer trips to the grocery (more time saving and less gas!). Keep a running list on your phone or fridge.