A few weeks ago, I wrote about the discount supermarkets in the Chicagoland area. Since then, I've tried a system for shopping at these stores.
I make a list - and stick to it. Then I go every two weeks. I do a circuit. First to Aldi, then to UltraFoods to get the items not carried at Aldi and brand names.
So far it's working and I AM saving money. Aldi's private labels are good and taste very much like the national brands. The savings are worth the effort. Anything I can't get there (usually cereals, specific brands, and less basic items), I can get at Ultra.
I bring my cooler to keep frozen and refridgerated foods cold during this trip.
While it takes some time, I'm only going now every two weeks. I hope I can make this work during the school year when it's a bit harder to find large blocks of time, but hopefully by then I'll have this system finely tuned!