Start with what you already own

Most weekly food bills aren't driven by the price of a single item — they're driven by buying things you already have. Before you write a shopping list, spend ten minutes doing a proper audit of your kitchen. Open the fridge, pull out the vegetable drawer, check the freezer drawers and dig to the back of the cupboard where the half-used bags of rice and lentils live.

Make three piles, or three notes on your phone:

• Use first: anything close to its date, plus open packets and tired vegetables.
• Already have: pasta, tins, spices, oils, frozen peas, stock cubes. These are the backbone of the week's meals.
• Genuinely need: the gaps — usually fresh produce, dairy, bread and protein.

The average UK household still bins a meaningful chunk of the food it buys every week, and most of it is perfectly edible when it goes in the bin. Treating your own shelves as the first shop of the week is the single fastest way to cut that waste, and it costs nothing to start.

Let the offers shape the week, not the other way round

Supermarket offers are only a saving if you were going to buy the item anyway. A three-for-two on something your family won't eat is just a more expensive way of buying one. So work in one direction only: check what's reduced or on promotion, then decide which meals that makes cheaper this week.

The categories where offers genuinely pay off for a family budget are:

• Fresh meat and fish near its date — buy it, take it home, freeze it the same day, or cook it that evening.
• Frozen vegetables and fruit — nutritionally comparable to fresh, no waste, and often on a two-for-one.
• Tins and dry goods — chopped tomatoes, chickpeas, kidney beans, pasta, rice. Long shelf life, so bulk buys carry no risk.
• Own-label staples — flour, oats, butter, cheese, yoghurt and tinned goods are frequently made to the same standards as the branded version at a lower price.

Ignore the multibuy on crisps, biscuits and fizzy drinks unless they were already on your list. That's where the "savings" quietly disappear.

Build a simple weekly meal grid

You don't need a colour-coded planner. You need seven dinners written down somewhere everyone can see. A pattern that works for a lot of households is to give each night a job rather than a specific recipe:

• Monday: leftovers from the weekend, or something from the freezer.
• Tuesday: pasta or rice-based — cheap, fast, endlessly variable.
• Wednesday: mince night — bolognese, chilli, shepherd's pie, meatballs.
• Thursday: something with eggs, beans or pulses, keeping costs low.
• Friday: homemade takeaway — curry, pizza, wraps, chips in the oven.
• Saturday: the meal someone in the family actually looks forward to.
• Sunday: a roast or a big one-pot that deliberately makes extra.

Breakfasts and lunches benefit from the same treatment. Rotating two or three options — porridge, toast, cereal; soup, sandwiches, leftovers — stops you buying a different lunch every day and throwing half of it away.

Cook once, eat twice

The biggest hidden saving isn't in the shopping trolley, it's in the cooking. When you make a bolognese, double it. Cool half, portion it into containers and freeze it. The same pan, the same hob time, and one night next week costs you nothing but the electricity to reheat it.

Other reliable multipliers:

• A whole chicken becomes a roast dinner, then a curry or pie, then stock from the carcass.
• A large batch of tomato sauce covers pasta, pizza bases and a baked-egg breakfast.
• Jacket potatoes, roasted veg and cooked grains all keep for several days in the fridge and can be fried, warmed or turned into soup.
• Bread going stale becomes breadcrumbs, croutons or a bread-and-butter pudding.

Label containers with the date. Anything unlabelled becomes mysterious and gets ignored.

Keep a running list and know your prices

Over a few weeks, note down what you pay for the ten items you buy most often. You'll quickly spot which shop is cheapest for your particular basket, and which "bargains" aren't. Prices change constantly, so a note on your phone is enough — you're looking for patterns, not precision.

A few habits that reliably trim the weekly total:

• Shop with a list and a rough figure in mind. Decide the budget before you go, not after.
• Do a flexible final meal. Leave one night unplanned and build it from whatever needs using up. Call it fridge roulette and let the family join in.
• Check dates when you buy and choose the longest ones for anything you won't eat in two days.
• Shop online if temptation gets the better of you. A basket on a screen is far easier to edit than an aisle of offers.

None of this requires spreadsheets or a rigid routine. Ten minutes of planning on a Sunday evening, one honest look at what's already in the cupboard, and a willingness to let the offers — not the recipe book — decide the week's menu will do more for your food bill than any single money-saving trick.