Make a shopping list before you go to the grocery store. This will avoid impulse buying. This will also help you remember to buy the things that you need and avoid several trips to the store.
Sort your shopping list. Write down all the items that you'll find in the same aisle, i.e. list all dry products together, meat products on one column, fruits and vegetables on another column, etc. This will save you time at the grocery store.
Use store coupons. You can find them in newspapers and flyers.
Look on the top shelves. Most stores put the less known brands (less expensive, too) on the top shelves. The more common brands (more expensive) are on the lower shelves, or on your eye level, to attract you, the consumers.
Buy store brands or generic brands, they're a lot cheaper. Every cent that you save on each item will add up to $ in savings.
Buy in bulk. Not only are you saving money, but you're also helping the environment with less packaging. Be conscientious, though. Do not buy perishable items in bulk if you won't consume all of them before they go bad.
Buy fruits and vegetables that are in season. They are cheaper and fresher.
"Mommy, I want that! Mommy, buy me this!" Sounds familiar? Well, leave the kids at home. (Just kidding!)