Hang the piece. Ensure that the piece is hung properly and does not easily move when placed on the wall. When lighting a piece, you will require some extra space for the lights, so do not place the piece too close to other pieces or to furniture.
Choose your bulb. Several bulb types are available for lighting a piece and the choice of bulb will depend on the piece itself. Incandescent bulbs are good if you want a warm color; halogen bulbs emit a white light that is best for bright illumination -- however, they become very hot, so must not be placed close to the piece; fluorescent lights are least desirable for lighting art, since they emit ultraviolet rays that can damage pieces in the long run.
Attach the light. Lights can be attached to the wall on a mount or through being screwed directly into the wall above the piece. Alternatively, lights can be affixed to the frame via a light track or scope, both of which are available at most hardware stores or lighting stores.
Position the light. Choose a proper length based on how much light the piece requires, which will depend on the colors in the piece, the light in the room, and the color of the wall. You can experiment with the length and position of the light, especially if the light is attached to an easily manipulated telescoping rod. However, do not place the light too close to the piece, since heat damage can occur.