If you haven’t noticed rising prices at the supermarket lately, it could be you haven’t been paying close attention to your spending. That is why a grocery list is convenient for your regular trip to the market, separate food and non-food items. You know the basic rule, sticking to your list and keeping your budget to avoid excess buying.
I also find it helpful to list down meals that you would like to cook for the family. I have mine for a whole month, alternately I listed dishes for chicken, fish, beef, pasta and a bit of pork (we are not fond/fan of it).
So far, my trips to the grocery were not erroneous. I haven't come home from the grocery store with things like oversized vacuum bags, industrial hand wheels, chocolate syrup for ice cream, sour cream and too much chocolates. ;)