The first is to go to the supermarket. Some local supermarkets have gotten into the habit of pre-packaging set quantities of each food, so as to skip the step of you having to pick each piece of produce individually, have it weighed and priced. Personally, I'm not fond of that method unless I'm in a big hurry (which does happen to be the case more often than I'd like!).
I prefer to choose my produce by myself.
For environmental reasons, I like to see produce that is free of plastic or styrofoam packaging. I think packaging is one of the great evils of our age!