Making a shopping list inevitably saves you money if you stick to it; it's when you meander around the shops picking up 'what looks nice' with nary an idea of how you intend to use it that you fritter your pennies away. The excuse that "I wait to see what's on special offer" is no excuse really, lists of all the supermarket deals can be found online, via their websites. Try somucheasier for a conveniently grouped list of all the stores' sites. Plan your meals according to what WILL be on offer.
If this sounds preachy, I'm honestly sorry, it's not meant to, but I save so much by shopping this way that my list for the week can always include a few treats; some nice wine for the weekend, a trip to the cheese shop for a beautiful piece of cheese to go with soup and bread, or some delicious olives and chorizo from the Spanish deli; I want others to enjoy these little pleasures too. Plan midday meals too, if there'll be people in for lunch, or just build in a few simple options to your list. Likewise with breakfasts...
When you have children of school age, the other advantage of meal planning is that you can check what the next week's school meals will be and cater accordingly, even my children would baulk at the idea of spaghetti Bolognese for supper if they had already eaten it for lunch at school. Our local council, in Ceredigion, provides parents with a copy of the 4-weekly rolling menu and I'm sure that can't be exclusive to that one authority. So useful to keep track of what they're eating and plan your family meals at home accordingly. If your school doesn't provide you with this, ask them; even if they only put the menu on their website it would help, but I would think that most schools would be only too pleased to accommodate a genuine interest in improving the family life and well-being of its pupils. Happy planning!