Set a budget for your shopping. Do it for the week or just for a particular meal, and don’t go over it. Professional chefs work out the price per person for a reason.
Batch cook at the weekend. It could save you time and effort during the week, and freeze ahead for lunches, instead of buying from a shop each day.
Embrace ‘wonky’ vegetables. There’s no need for a perfectly straight carrot if you’re making soup, so why pay more? Many supermarkets now sell wonky veg at a lower price.
Points make prizes. Use those loyalty points you’ve built up, perhaps treating yourself once in a while as a reward for sticking to your budget. And look out for opportunities to ‘trade up’ and exchange your points for restaurant or experience vouchers.