How often do you shop and for how long does the food from your shopping trip last?
Do you know what you will eat for the entire week and then shop accordingly? Or do you just shop and end up getting what you normally get?
As stuff is used up it goes on a list. Once the list is long enough or we’re out of something critical, we go to the store. Once there we buy the list and maybe some other unplanned interesting things that are on sale or catch our eye.
Our stores are close enough to home that we often stop by for only 2 or 3 things simply because we’re passing them in the normal course of getting home from wherever.
We also have a back stock “policy” that’s related to longevity. If the stuff keeps for months, buy two or three to start then replenish one as you use one, so there’s always one or two on the shelf unopened and it’s never a crisis when a container is emptied. e.g. peanut butter.
Conversely, if the stuff keeps for just a few days, buy small amounts often. I probably buy fresh fruit and veg 2-3x every week, about a pound each at a time.
There’s just two of us and we eat almost entirely fresh food; we’re not feeding an army of kids. So this works for us.
When we run low of staples, we write them on a white board. Otherwise I decide what I want to make, put it on a list, and go to the store to get it (plus anything else on the list).
Menus are made and inventories are taken. Then we shop for about 2 weeks worth of everything but produce. That I can pick up on the way home from work at the local farm stand, 4 different grocery stores or various truck stands. Once a month we hit Target or Walmart for cat food and certain other items which are so much cheaper there.
Once a week, almost always on Saturday. For meat I go to the butcher, usually Saturday also, but could be any day that’s convenient. I try to have enough food for the week, and that’s not very difficult. We’ll have leftovers at least once in the week, we’ll get take out or go out to dinner once a week, sometimes more often. Without the kids at home we don’t need that much food.
I prepare a list of things needed before going. I read the sales of the store. If there is something at a reduced price, and I like it, I buy.
As my mother used to say, “If it is not on sale, you don’t need it”.
I live very close to a grocery store. I make small lists of foods that I’m out of and go to the store as needed. I shop the perimeter of the store starting at the deli, wine aisle, dairy, meat and produce. Then I get staples. I rarely have more than one or two dinners planned in advance, but I can also prepare something wonderful out of practically “nothing.” It runs in the family 
To an observer my strategy would seem to be to spend as much money as possible in as many trips as possible.
We plan the meals for a week based on what is in the freezer or in the garden and what is on sale. We go online and do the on-line coupons - the Safeway personalized coupons are better than the regular ones. Then I rewrite the list in the order they appear in the store, and we zip through it. We seldom buy stuff on impulse unless there is meat or fish that has been heavily discounted.
We definitely buy ahead when stuff is on sale. We have coffee for months, and I got a load of soda when it was cheap. We go to Costco for paper goods.
I usually take lunch, and we’ve been making meat big enough for leftovers on weekends - like a pork roast we have in now. Much cheaper than deli meat and better.
Eliahna, I was afraid that I was the only one.
I try, really I do. But lately I’ve been working 60±hour weeks. I’m not hungry when I get home, normally, and I really can’t face cooking. So if I manage to eat Greek yogurt and fruit for dinner and not chips and ice cream, it’s a win.
This weekend, Im working on getting a stock of “nukeables” – mostly soups, but some casseroles and other stuff in single servings, too. I’ve done pulled BBQ chicken and chicken and wild rice soup so far. I’m going to make some baked pasta tomorrow (mmmm).
Once a week I go online and order from a Supermarket’s Warehouse (i.e large choice.)
They deliver to my door the next day - and then unpack all the shopping for me. 
The delivery costs £1 ($1.50) - seems reasonable!
5-6 times a year, we do a huge trip at the area’s cheapest store, looking at items we normally buy. Usually we screw up, either by not defrosting a hunk o’meat, or not having a palatable vegetable available, and wind up with a couple of jaunts per week to buy dinner fixins.
When I was single, I chose a single supermarket (compromise between price and quality), and dashed through about once a month, always buying the exact same items. I supplemented with vegetable rich restaurant meals.
Circumstances, several years back, forced the mister to do the marketing. He learned what brands I wanted, what to look for in fruit etc. He got really good at it. And though those circumstances have since evaporated, he remains quite dedicated. As in, he reads flyers and chases deals. Since I often need to go to the Asian market too, marketing can be an adventure. We have a walk in pantry and a freezer and he takes pride in keeping them filled to over stocked.
However, I do all the cooking, meal planning and list making. Same as others, I list what I use up, and buy a similar selection of fruits and veggies each week. It shifts a little seasonally, and the fridge is pretty empty by every Saturday, when we shop again.
I buy ground beef five pounds at a time. I weigh out one-pound portions on the kitchen scale, putting each portion into a fold-top sandwich bag. I push as much air out of the bag as possible, then put the parcels into a one-gallon zip-top bag (with as much air as possible taken out). this goes into the freezer, and it’s easy to pull out a single pound that is easy to thaw.
We go through the sale papers, husband cuts coupons, we talk about stuff we’d like to have in the near future, make a list, double check staples and add them if necessary, go to the store, realize we forgot the list and just shop. If we see something good, we get it. If we’ve already decided in advance about something we want, we buy it. We usually go there every other day to two days, so if we forget something or change our minds, we get it then. The store is less than a mile away - it’s no big deal. And I keep coupons in my purse if I think it’s something I need, just in case we remember - because we keep forgetting the list.
Once a week to the local supermarket, buying mostly stuff that’s on sale outside of the stuff like milk, eggs, and lettuce that gets eaten continuously regardless. Every once in a while to Costco once we run out of something that we get only from there, stocking up on anything else that’s low.
I go to the fridge / freezer / pantry and decide what to eat based on what I find. I think it is put there by elves or fairies. They seem to do it on the days my wife is in town taking care of her mother.
Once a week, on a week day (the biggest perk of retirement), and about mid morning. Stores are nearly empty at that time. We usually go on a Tuesday, as there is a 10% across the board discount for military, active or retired. On Wednesday, we hit the farmers’ market for fruit and veg.
I’ve got a list organized by store aisle with all the things I normally buy at least once per month. Each week, I write “yes” or “no” and any quantities next to each item. I use this for my main shopping trip on Thursdays. I write any needed additional items on my daily list of things to do and buy them on Mondays, unless it’s a holiday, in which case I pick them up on Tuesdays.
I used to go weekly to check on the specials. But when our fridge died a couple of weeks ago and the replacement had a smaller freezer, I’ve quit shopping till we eat down our surplus. I’ll be going in a day or two for eggs and cheese, but we’re good for most everything else. And now that I’m going back to work, I expect shopping will be me grabbing something on my way home to make a quick dinner.
We shall see…