I probably have the least organized grocery system of any homemaker I know. I'll confess: there is no weekly grocery list. While my style is a bit more by-the-seat-of-my-pants, I manage to put healthy meals on the table and keep my $50/week budget in check. My two big tools are from the Tightwad Gazette: the price book and the pantry principle. The oft-touted price book is simply a way to track your lowest price per item for the stores in your area. I update mine more infrequently now that I've been shopping so long. Still, it's essential for those odd-ball items or shopping trips when you just can't do the mental math.
Second, and perhaps even more important, is the pantry principle. When you see one of your regular products on sale, stock up! What's more, get enough to last your family until item goes on sale again. Your price book can help you track the cycles. I thought I had made a big mistake when Ragu introduced an organic line this year. I bought two dozen for $1 apiece. Just as we were running low, Harris-Teeter put all its Ragu, even organic, on sale again. This time I knew exactly how many jars to buy. (Ragu is not my most favorite sauce, but I'm willing to be flexible for the organic Garden Vegetable.)
Today's shopping trip was no exception. If you looked at the food I brought home, you might wonder, "What kind of meal can come out of three jars of sugar-free jam, all that Ragu, two loaves of bread and six packs of cheese?" But, combined with weeks of similar shopping, I have enough ingredients on hand to make several tasty meals without the help of grocery list.