First, we need to buy only what we really need.
Second, it helps to buy large quantities of frequently used bargain items. Some ways to do that are joining places like Costco or Sam's Club where things are sold in bulk, and shopping at outlet stores. If storage space is a problem sometimes two or more families can share the cost and split the purchases.
When something we often use is on sale it's a good idea to buy two or three times the usual amount. But before using coupons or purchasing sale items check the prices of similar things. Sometimes other brands have everyday prices that are lower than the cost of the products on sale.
A clothing swap between families can be fun.
Some people are embarrassed to shop for clothing, books, and household items in second hand stores, but there's no reason to be. I can't buy used clothes anymore because the fragrance in the products the stores used to wash or clean them bothers my allergies, but I used to do that. I always felt proud when I could find something like a gently used designer suit for only a few dollars.
Another way to save money is to cook food from scratch and eat at home. With practice it's possible to cook enough dinners for a whole week in a couple of hours, and just reheat things each evening. Alternating between several kinds of food and freezing extras keeps the menu interesting and the meals can cost a lot less than frozen meals or fast food.
If money is tight there are still a lot of fun things for families to do. It doesn't need to cost anything extra if families take turns inviting each other over for dinner, but they still get the pleasure of eating out. If the kids in each family prepare performances for their guests that adds to the enjoyment.
A picnic at a park or beach, playing games together, or going for walks usually don't cost a thing. Other cost-free things families can do are singing together and reading books out loud - not just bedtime stories, but fiction the whole family will enjoy. Some classics are great to share that way.
There are many ways we can pinch pennies and still have enjoyable lives.