Old Dog and I have a system worked out for buying groceries.
Each Saturday, I record everything we need for the week on a pre-printed form that lists, in order, the aisles at our local supermarket. I write down, very specifically, the brands, flavors, sizes, etc. Then he takes the list and, with the blood of the ancient mammoth hunters flowing through his veins, tracks down the items on that list.
We don't do this, as you might think, because I'm a control freak. We do it because Old Dog prefers it that way. (The satisfaction of my inner dominatrix is a byproduct).
And, lest you think that, at our house, it's all about me, Old Dog has the right, and the privilege, of choosing pretty much all the snack foods. I am on a mission to maintain, my weight, so I try to ignore the snack food aisles on the list.
He generally keeps us supplied with lots of things that, due to my allergies, I can't eat, so it works out pretty well.
Except at Halloween. This time of year, I'm forced to provide a little helpful input about the importance of good nutrition.