When you look at an object in real life, it is three-dimensional, and everything that surrounds it provides a sense of proportion and scale. In a photograph, everything is translated to a two-dimensional space and reduced in sizeresulting in a loss of quality and detail. One of the major mistakes that beginners typically make is shooting too far away from the subject, because they look through the viewfinder and try to replicate what they see with the naked eye. Instead, I like tight shots that are full of impact. They give viewers a sense of perspective and reality that is different from their normal viewing experience.
Often, I accomplish this with a telephoto lens. A telephoto lens makes things look closer than they are. It also, however, compresses the distance between objects and narrows the field of view. Using a telephoto lens is like looking through binoculars or a mini-telescope. You can simulate this effect by using your hands to cut off part of your peripheral vision, reducing your angle of view as blinders do on a racehorse.
When using a telephoto lens, you must back away from the subject and hold the camera steady. Because telephoto lenses are heavy in general, it's hard to shoot handheld at a slow shutter speed. The best solution is to use a tripod, or to brace the camera on a solid surface.
In addition to using a telephoto lens, employing a low angle and shallow depth of field helps give a picture impact. These are perspectives from which people don't normally see their food, because they usually sit at a table and look down on it. Combine these approaches with an interesting composition and you'll have a great photo!
Good cropping techniques can also help fix compositional problems by eliminating unwanted material from the final image. That said, it is better to frame the photo properly when taking the picture than to rely on cropping afterward because superior final quality is achieved by using the full surface area of the camera's sensor to capture the image.