We may be able to walk to work or not buy clothing for twelve months to cut costs, but everyone has to buy groceries.
Making a list is a simple yet vital way to save money. It's good to check the main supermarket specials for half price or better deals also. Be aware that supermarkets will have an item on "special" but it may only be a few cents off the normal price. Check your stock items and staple foods and if any need replenishing add them to the list. Keep a list running and add to it so you don't forget a vital item. This will also save the transport costs brought by the dash to get a vital ingredient!
Always avoid shopping for food when hungry. You need a substantial meal before you go. Even if you can resist all the temptations while hungry you will feel horrible. Being in a bad mood plus feeling rushed to get something to eat will not help your shopping experience or choices!
Buying fruit and vegetables in season makes them cheaper and fresher so it's worth finding out what's in season and working a menu around it.