A popular strategy in food photography is to selectively focus on one particularly appetizing part of the dish and let the rest blur a bit in the background. Bokeh is the artful blur of the background, or the way the lens renders the out-of-focus parts of the pictures as soft blurs of light. By using selective focus, and plenty of beautiful bokeh to bring the viewer's eye right to a certain part of the photo, the viewer can feel like they're right there in front of the food and could reach right out to taste it.
Not only does selective focus draw your viewer in, but it also makes the dish look less busy and complicated. Instead, it just looks delectable. Use a macro setting on a point 'n' shoot camera, or stop down your aperture on a dSLR. For instance, on a 50mm lens, stop down to f/1.8 or f/2.0 for a really shallow depth of field that focuses in on just a single cookie on a plate, or just a few nuts in a bowl full of them.