Warning - long post! We have recently changed how we cook and eat and it has greatly reduced our food shop bill and that has surprised me. I need gluten free and vegan so some items cost a lot more than your general basics. We used to have 5 of us at home and our food bill was huge, but now myself and my husband are empty nesters. That's been the case for a year and our food bill was quite steady. However, our food bill has changed a lot over the last month. We used to cook our main meals and use the leftovers for lunches, especially me because I work long hours and need to take food with me.
Instead of doing that, we have been splitting what we cook across 2 evening meals e.g. bolognese, chilli and curry and reheating on the second night. We are doing that at least twice over the week (so 4 meals, or 6 if we can). We realised that the amount of veg we were putting into meals for the 2 of us hadn't changed much compared to when we were cooking for 5, so we don't have to add much extra (e.g. an extra can of chopped tomatoes and more herbs) to make the meal feed us for 2 nights instead of 1. I am then taking other, simple things to work for lunch made from the extra bits of veg that are left in the packs we got for other meals, along with cooking a little extra rice or pasta alongside whatever we are having, or using the veg to fill pitta breads. I am taking more fruit with me too.
We always planned our meals before and always tried to use up leftovers, but we've vastly reduced our food waste doing this and our last few food shops have been noticeably cheaper.
For us, which wouldn't affect someone eating meat, there are a couple of things I buy in a tray from Amazon now and that saves quite a lot too. I know this is mumsnet and people do amazing things in terms of meal prep and getting loads of meals out of one thing they cook. What we are doing is way simpler.
We do eat lots of things like lentils, which I know some people wouldn't want to do. I have stopped buying plant milk and make it now, but that would only have made a little difference, I think - I wasn't having tonnes of the stuff before. We eat lots of different beans too, but tend to get organic canned ones rather than dried. I totally appreciate some people wouldn't want to do that, but there's not much comparison between the cost of a can of organic butter beans and the cost of 2 portions of meat, I suppose.
It's just shocked me how the small change of how we're cooking has made so much difference. The first week, I just thought we just didn't need to get so much that week in our shop. It's carried on though.
We do shop online for food as much as possible, as we get very easily distracted by things we don't need in a store. Plus, we then check what we have and see if we have enough for what we're planning. We also try and start our meal plan from what we already have here to use it up. It's all basic stuff lots of people are probably doing anyway.
We're really enjoying the food as well, importantly! We didn't do it this way to make savings - we were just being practical during a busy week initially. It's our favourite meals we are doubling up on too.
We tend to alternate the meals so that leftovers are eaten 2 days later than the first meal. We thought we were just cooking the same food in a different order, but it is making more difference than we thought.
I don't very often shop in the budget supermarket near us as we can't quite get what we need from there and it doesn't seem to save us money - it works best for us to do the online shop. We're big eaters - we like big portions!
I feel like (strangely) we're having more things that feel like luxuries too. If we want something like pizzas, the ones at Morrison's counter are amazing and 2 for £5. There are cheaper pizzas available, but not vegan and gluten free options. We like these the best too and they really pile on the toppings. Plus, you can see them make them and know they are being careful re: allergens. We don't get those online though, but luckily the counter is near the door, so it is possible to get them without buying loads of extra things!
We do try out new products if we come across them and they interest us, but I am aware that the cost of the rest of our meal probably balances that out. We are generally using our Instant Pot or air fryer to cook and so our energy costs are really low too. We love shoving potatoes and other veg we have in the fridge into the air fryer at the weekend with some veggie sausages and we feel like we've had a roast dinner that way. It's all easy stuff.
I am sure there will be ways you can slightly change what you are making that will make more difference than you expect too.
I am sure you will have loads of great suggestions on here too. I haven't read through them all.