My strategy is simple: in general I avoid food that a hunter-gatherer would not be able to find. I said "in general" because I eat cheese, some hams and preserved meats and sausages, and I also drink wine.

After a short learning curve it became very easy.

In terms of convenience, I still find a sandwich and a canned juice pretty convenient, but I avoid them anyway. I have not had the need for other "convenient" foods like cereals, rice, noodles, and so on.