I like to think I'm relatively free from these influences.
When I cook at home, I like to make things from scratch if I have the time. I don't always have the time to make chicken stock, which I use a lot of, and I have recently (in the past few years) started cheating by using tomato sauce from a jar or pre-made pesto, for example. Before that, I used almost no pre-prepared foods, although I've always bought bread and such because I suck at baking. The sauces and things I do buy are usually from small companies made here in town.
I don't watch tv so that eliminates cooking shows and advertising, for the most part. I might see something I like the look of in a magazine once in a while, but I'm not one to run out and buy a cutlery set, since virtually all my kitchen utensils are hand-me-downs or things I found at the thrift store.
I shop at smaller local markets and specialty shops. The produce I buy tends to be grown here in the area, since we are surrounded by farms here. As for fish, we catch a lot of that here in the Monterey Bay - I buy local fish when I have the choice. I'm pretty picky about freshness because my last boyfriend was a commercial fisherman, so if stuff got any older than a day or so, we just gave it to the cats.
Basically, I'm a marketing researcher's nightmare!