This is another of those nice areas where we get to ask an obvious followup question, shop for what?
Everyone is different, but here’s one method that works.
Shop for non-perishable commodities much less often than you shop for perishables.
For the basic commodities of life, you know what you use, and you can go to the big box store or the membership warehouse and stock up. You may go weekly, looking for what’s on sale. When you find something at a genuine savings, that you know you’ll use, you can take advantage of that up to the limit of your reasonable storage ability.
But the big box store, or the membership warehouse, is probably not a great place for healthy minded folks to shop for perishables. I really don’t want a bag of ancient fruit, I want the pretty, in season fruit that just came in today or yesterday. Personally I shop for fresh food every couple of days, because that’s as far ahead as I can predict who’s going to be at home and how much time we’ll have. If there’s some non-perishable we’re totally out of, I could get that at the smaller, fresher store, at a premium, and that’s OK. I know if I run into the big store to get that one thing, I’m likely to get five other things that outweigh the premium I paid at the small store.
For that big box store stuff, right now we’re experimenting with buying some of that via Amazon Prime, which we already use to get free 2-day shipping. We can time the free delivery of stuff that’s hard to find or inconvenient to tote home, at a price that’s a little less than the store.
Should you always shop with a list? Yes, most definitely for the big things at the big store where it’s easy to over-buy, and probably No, for the perishable things you’re going to eat over the next couple of days. Even with a pretty decent knowledge of what’s fresh, or a handy site like this one, there’s an amazing variation from year to year on what’s especially good. Right now grapes and apples are awesome here, as I know from the samples at the grocery yesterday, so grape-apple chicken salad is on tomorrow’s menu just because we can.
More or less often? Try doing both.