If you have access to a white photography backdrop use it. If you don’t you can create a makeshift backdrop from an ironed heavy white bed sheet. It is extremely important that the bed sheet be ironed. I cannot stress this enough. Fold marks or creases in the background of the photograph will make you look unprofessional. Another important element to consider is the whiteness of the sheet, do not use an off white bed sheet. If you sheet appears translucent, double up the sheets to provide an opaque backdrop.
If your sculpture is large you may want to photograph the work in an environment. If this is the circumstance try to photograph the work against a neutral background, such as an empty white wall. You do not want the location’s background to be distracting the viewer from the artwork.
Use a tripod to photograph the work. If you can, photograph outside. If you photograph indoors turn on as many lights as possible, use a bright room with lots of windows and natural light. If you need extra light and don’t have access to professional lighting systems borrow some lamps, take their shades off and use white light bulbs.
When photographing the sculpture make sure to take photos from every side. It is very difficult to get a sense of a 3 dimensional object only from one photograph. Usually you can submit several images for sculpture. Take the photographs from advantage points that highlight your sculpture.