I find that when I don't snack and I consistently walk past cakes, sandwiches, etc. in coffee shops, I save a lot of money. For the grocery foods, it depends. I know now where to buy the cheapest nuts, seeds, coconut oil, etc. I get away with cheap meat, thanks to my slow cooker and the guts to try different types of meat, and cheap veggies at the market. Just today I bought 5 courgettes, 2 huge (really huge) broccoli heads and a bag of red peppers for altogether £3.