Wise up! You’re spending too much on groceries.

Probably the biggest reason for shelling out more than necessary is having no flight plan. You can’t just get in the cockpit and see where the plane lands. Taking that approach to shopping guarantees you’ll gasp when the supermarket checker announces the total.

Let’s get started. We’re going to focus on dinner. Later you can apply your system to other meals and office lunches, and more.

First, in advance of making a shopping list, sketch out a week’s dinner menus. It’s a mistake to think you can do this in your head at the store. Posting a menu list on the fridge is your quick reference and lets your household know what to expect. No one is asking what’s for dinner at 4 p.m., when you’re trying to wrap up the work day. It eliminates the need for a short-order cook, and it discourages grumpy members of the household who announce what they like and don’t like (let them talk to the fridge). And there’s a fringe benefit: You can ask someone to prep something from the list to get the dinner show on the road. You can do pizza night and takeout night, just write it in.

Now the fridge. I open refrigerators in friend’s homes and I practically faint. How can they organize dinner every night if the place where they keep the food is so chaotic?

Money is sitting on refrigerator shelves till it’s past the sell-by date. Pull out what’s been pushed into the back. Your menu planning shouldn’t be so strict that it can’t take into account things that just accumulate the way they have a habit of doing. On a night when you find bits of chicken, the end of a package of sliced ham, a tomato that’s lost its luster, you’ve got dinner. Make an omelet or frittata, or pack it into a tortilla. If you were going to toss out these oddments, consider this a free meal. Every week, there are free meals in your fridge. Turn them into a soup, a curry, a stew with a can of beans added for heft, burritos, stuffed pita pockets. Leftover night is the quickest meal you’ll make all week. And the improv is fun.

This system does mean being organized, keeping track of everything in the house. Labels! says your Type A adviser. Get a roll of tape and a Sharpie and label everything on the side of the container (not the top, unless your freezer is a pull-out drawer), so you can see at a glance. And then, though this is obvious, but I might as well hammer it home, cluster like ingredients together.

When you make the grocery list — and you must have a list so you’re not shopping willy-nilly — keep all the produce together, and the dairy, and so on. This prevents detours into aisles where you don’t need to go.

See if you can reduce the amount of partially prepped or fully prepared food in your cart. Broccoli florets already cut up will save you 10 minutes; same for cut-up watermelon. But don’t forget, everything that someone else cuts for you costs you. For example, the cheapest way to buy chicken is whole. There are a zillion YouTube videos to demonstrate how to cut one up and if you butcher it, so to speak, it’s going to be cooked later and no one will notice your mistakes. As for national brands vs. store brands of chicken, we did a tasting last year and discovered that a supermarket brand ranked as high as a locally raised organic bird.

Always opt for blocks or wedges of cheese, rather than packages of grated or shredded cheese. It’s less expensive per pound and the cheese is fresher, more flavorful, and free of anti-caking additives.

You may have to change brands or re-create in your own kitchen what you’re buying ready made. A particular brand of chicken fingers might be the most popular item in your household, but your family will get used to homemade chicken fingers if that’s what’s on the table that night (they’re terrific!).

If you want to buy chicken parts, buy bone-in thighs or breasts, which are more economical than boneless cuts; cooking meat on the bone produces juicier flesh. Pull the meat off the bones to serve it and freeze leftover bones in a zipper bag. When the bag is full, make stock by putting the bones into a pot with a halved onion, a couple of carrots, and water to cover generously. Simmer it for an hour and use that stock in other dishes.

Shop the sales, of course. In the industry, these are “loss leaders.” It gets you into the store, hoping you’ll leave with $50 more groceries you never intended to buy. Say you’re going to the supermarket to get a rotisserie chicken on sale — even full price they can be less expensive than a whole uncooked bird — buy it. If you’re just shopping for rotisserie chicken, you won’t get sucked in to everything else in sight because you’ve got a plan and a list. If there’s a cut of meat on sale, buy several pounds. Use one for your weekly menu plan and freeze the other two.

If you find that your family eats a lot of rice, lentils, and pasta, make a double or triple batch. You’re done for the week. They microwave back to life in minutes. Never roast a single chicken or make a single meatloaf.

If a recipe calls for a can of tomatoes, add half a can and fill in the rest with water. Use water instead of, or in addition to, chicken or vegetable broth, or instead of wine. Water is a trick centuries of good cooks have used. Add herbs and spices to boost the dish. You can extend fruit juices with water, too.

If you’ve got your kids’ friends dropping by for dinner all the time, or you need food on hand after a game or practice, keep make-ahead grilled cheese sandwiches in the freezer. Use an entire loaf of bread, wrap sandwiches individually in plastic wrap, and slide into a large bag.

If you’re making a beef or shrimp stir-fry, use half the meat or seafood called for and supplement with extra vegetables. You’ll be just as happy.

Fans of nut butters who have a high-powered blender can make them at home. Instead of whole nuts, grab the less-pretty, but more thrifty, nut pieces (peanuts, almonds, cashews, pecans). Add a few cups to your blender with a pinch of salt and in a wink you’ll have smooth and creamy nut butter.

In the recession of 2008, I spent a year buying only food on sale. I thought that if I was going to write about cost-saving recipes, I should put them into practice. I bought cuts of meat I had to Google to learn how to cook, fish sitting at the far end of the case because it wasn’t popular enough to be front and center, unfamiliar legumes and pulses from supermarket bulk bins. I entertained all the time. I remember a pot roast that took four hours to be palatable (thankfully I made it a day ahead). We ate well. Nothing went to waste.

You will eat well, too. Your piggy bank will gain weight. Give that Sharpie a workout.

Contributions to this story were made by Claudia Catalano and Caleb Barber.

Sheryl Julian can be reached at sheryl.julian@globe.com. Follow her on Twitter @sheryljulian.