I suggest taking a pen and some paper to your local store and write down the prices of your most commonly purchased items. Then every week or so check those items to see when the prices change. When you have a coupon for a certain item and you catch that item on sale you have saved even more. Now keep in mind that some stores will not allow you to use your coupon on their store's sale day. Check out how your favorite store works with this sort of situation.
Some grocery stores will double the coupon. Twice the savings! Always be careful to buy only the items that you will use. Buying something just because of a sale or because you have a coupon for it is not saving if the item is not needed.
Always check the expiration date on the coupon before you go shopping. It will save some embarrassment at the checkout counter.Remember to take a look at the store brand item. Sometimes you can get a good store brand item for even cheaper than a non-store brand even with the coupon. Make sure that it is an item that you will use. A savings will not help if you would not use the item. I will admit that some store brands are not as good as non-store brands. However, I have found that most of the time they are of just the same quality. Think of spices for example. Salt is salt with or without the fancy package. So, do your homework and look for the best savings for your money.