While I won't pretend to know much about photography in general, I DO know that food seems to photograph best in natural light. I usually take food outside just out of direct sunlight to get a good shot.
However, it isn't usually sunny at dinnertime, and often I want photos of what I made.
Last night was a good example... I made a beef stir fry. This is an example of what a
flash can do to an otherwise tasty looking dish...makes it look like dog food basically. Ewwwww.
The light was pretty low in the dining room, but I took a shot anyway and worked with the exposure a bit on Picnik.