Most food waste is decided in the shop, not in the kitchen. People buy for the week they intend to have — the one with time, ambition and four vegetables a day — and then live the week they actually have. The gap between those two weeks goes in the bin on Sunday.
Buy for the week you will really have
Count the evenings honestly. If two of them end late and one is someone else’s turn, that is four dinners to shop for, not seven. Nobody has ever regretted buying too little fresh food; the shop is still there on Thursday. Buy fresh ingredients for the first half of the week and rely on the freezer and the cupboard for the second. Spinach bought on Monday for Friday is spinach bought for the bin.
Shop in the order things decay
Plan the perishable things for the first days: fish, salad leaves, soft herbs, berries, fresh mushrooms. The middle of the week belongs to sturdier things — root vegetables, cabbage, carrots, citrus. The end belongs to frozen, tinned and dried. That single ordering does more for waste than any storage trick, because it matches the shopping to the clock the food is already running on.
Do not buy an ingredient for one recipe
A jar or a bunch bought for a single dish is the thing most likely to be thrown away six months later. Before it goes in the basket, name a second use for it. If you cannot, buy the smallest size, or skip it. The exception is a store-cupboard flavouring you will genuinely reach for — mustard, soy, a chilli paste, a decent vinegar. Those repay themselves across dozens of meals.
Keep a short permanent list
Ten or twelve things that live in the house permanently make improvising possible: eggs, onions, garlic, tinned tomatoes, tinned beans, rice or pasta, stock, oil, vinegar, mustard, a hard cheese, frozen peas. With those, almost anything fresh you bring home becomes a meal. Without them, a fridge full of ingredients is still not dinner.
Look before you leave, not when you get back
Two minutes with the fridge door open before shopping prevents the third jar of mustard and reveals what has to be used this week. Take a photo of the shelves if it is easier than a list. And shop after eating, not before. It is the oldest advice there is because it is true: hunger buys food for a person who does not exist by the time it needs cooking.
Shop for the week you will really have, in the order things go off, with a permanent short list behind you. The fridge ends up emptier and the food ends up eaten, which is the only measure that matters.