I usually hit Denner first, then Migros for most milk products and Coop last since they are the most expensive. Also if you have an Otto's nearby they are cheap for shower gel, shampoo, dishwasher & washing machine detergents amongst other odds and ends. We also have access to Prodega so we can stock up on meat.

We budget 900 fr. a month for family of 3. What ever is left over goes in our 'holiday kitty'.

Check out here for weekly savings.