If you've got a couple of supermarkets close together, get to know which is usually cheaper than the other for certain products. I did this years ago when we were really struggling and have more or less kept on top of it. Our choice of meat, fish, eggs, cheese coffee tea, bread, crisps are definitely cheaper for us in Lidl, there are definitely cheaper cleaning products, toiletries and cereals there as well if you know your prices, and like other supermarkets they'll have their weekly fruit/veg offers. Cans, some sauces, toilet rolls and extra choice in Tescos, as well as convenience - one minute nearer home - which is another factor. There's only two of us and supermarkets are a ten minute walk, so we pick up what we can carry when walking through the village, meeting friends - right now making a concerted effort to do all shopping on foot as it'll save a little on petrol.
Lidl will be selling their 8p bags of veg over Easter, so guess others will be doing that for anyone who wants to stock up on freezing veggies, making soups which can be frozen. Lidl's veg at Xmas were far better than Tescos, where the carrots and parsnips were quite thin.
If you've got ok walks nearby, do those rather than spend money on taking the car out. We did one the other day and took a sandwich with us. Today, we've walked up the hill - we did buy coffee and cake for £12, in the village it's £14-16 for two.
Our heating is usually set on 18c, so luckily not coming on for long in the morning and not in the evening at all. Our DD was reduced to £100 last year an we're still in credit, so milder winters are helping to some extent.