I grew up in a multigenerational home where my mother and grandmother loved to cook. We always had a fully stocked fridge/freezer/cupboards. I do the same and always keep a good stock, I shop twice a week and just keep things topped up. If I see something I always use being sold as a special offer I buy a few extra.
I rarely run out of things. I don't meal plan as such but know I've got the means to make a number of meals, I also keep a stock of homecooked meals in my freezer.
I had a new friend visit recently and while we were chatting in the kitchen I decided to make some Welsh cakes to have with our coffee, she was shocked at the ingredients I had to hand and that I didn't need to go out to the shop.
Do you keep a well-stocked larder? I find it helps keep costs down, my grocery bill averages £100 per week for 2 adults and 2 teens.