Couponing has it's place, but what I've found is that it pays to know your prices and be willing to shop around. I shop at 4 stores, one weekly and the other three either monthly or every other month. I keep a price list of all my regular items for each store and update it a couple times a year. I know who has the lowest regular price on all that I buy, it also helps me figure out what is a good sale price (if an item is usually $2.04 and it's on sale for 2 for $4, I know right away it's not "stock up" worthy. But 10 for $10...heck yeah!).
Also start paying attention to sales cycles. For instance near the major holidays (T-day, Xmas, Easter) baking supplies and whole poultry/roasts hit yearly lows (plus coupons abound). Chicken in your area may hit "rock bottom" every six weeks or so. Stuff like that. This is also where price lists come in handy, it helps you spot the trends. Get to know when particular types of produce are in season too. Right now it's apples, for example. Over the summer it's berries, but Jan/Feb can be good for berries too as they are in-season in South American and are imported. Bananas are stable year-round.
Look into if your usual store(s) have digital savings program. My "main" store Meijer has a program that has digital coupons (store and manufacture) plus a rewards program that gives me $X off my next purchase if I spend $Y in certain categories each month. I've saved $240 just on the rewards program since the beginning of the year. As for the digital coupons, they allow me to stack store digital coupons with paper manufacture coupons, if I hit a sale price (I call that a trifecta) then I save a bundle (plus it counts towards my rewards total!).
Then there are the paper coupons that print when you check out. Those are "catalinas" (after the company that invented the machine that prints them) and are also very helpful. Often stores and/or manufacturers will run specials where you buy $X and get $Y off your next order. Sometimes these are advertised in the sales flyer for the store, other times you only know about them if you stumble across it or read about it on one of the couponing websites/forums (I like afullcup.com).
There are online coupons that you print. First make sure your local store(s) accept them, not all do. If they do, just watch what you print, cost of paper and ink can eat into your savings. Coupons.com, Smartsource.com, and Redplum.com are good places to start. Also check the websites of your favorite brands, they sometimes list coupons on their sites. The coupons sites often limit the number you can print of a certain deal, but if you have access to multiple computers you can get around that.
And then there are the good old fashioned Sunday coupon inserts. I have a subscription to my local paper (Sunday only). I clip what I like and try to keep track to make sure I'm at least saving the value of my newspaper subscription. I don't bother getting multiple copies (although I might if I found a killer coupon or two, but that's pretty rare these days).
Also, think outside the box a bit. I only feed my family pasture raised meats. Finding them at local stores is difficult and expensive when found. I did a bit of research and found a (somewhat) local farm, and I order from them 2x a year (helps to have a big freezer). I'd save even more if I wasn't picky about pasture raised and was willing to buy a 1/4 or 1/2 cow. CSA's are a good way to get tons of produce in the summer months, but require a significant investment in late winter/early spring, also you never know what you'll get so meal planning can get interesting. Alternately you can start your own garden at home, even a few tomato plants on your patio can shave a few bucks off your grocery bill (and taste better anyway!). Ditch paper towels and use washable cloths, and clean with vinegar/water solution and baking soda. I get the wash cloths, baking soda, and vinegar in bulk at Costco (a $20 bulk pack of wash cloths has lasted me 5 years now. a 10 pound bag of baking soda lasts a good year, including adding it to the laundry). Anything that you use that is disposable, see if you can figure out a way to substitute it with something reusable (this is also much better for the environment).
Watch waste. The most expensive thing you buy is the thing you throw away because it went bad before you used it (this goes for health/beauty items with exp. dates too). Monitor what gets tossed in your house and adjust the amount you purchase if needed. Also watch portions (especially meats and cheese). If your toddler isn't eating even half of what they are served, start serving them less. If you buy 3 pounds of strawberries but toss half away because they rot, it doesn't matter they were $1 a pound, you just threw a $1.50 in the trash. Try to use less cleaning products too. Laundry soap, I've found, easily gets my clothing clean when only using half the amount listed on the cap. Dry sheets can be torn in half (better yet, invest in dryer balls).