For this food shot I positioned the cookies on a white plate, poured a glass of cold milk and placed them on the back of one of my tower speakers. I used the black side of a 5-1 reflector as the background.
I setup a single Canon 580EXII flash with a paper snoot to direct the light onto the plate and milk without spreading to other areas of the image. This had the effect of really creating a black background and foreground around the plate.
Canon 5DII | Tamron 28-75 | f/10 @ 56mm | 1/125th sec. | ISO 100