Artists use the elements of light and shadow in their artworks by manipulating lighting to create contrast, depth, and mood. By strategically positioning light sources and shadows, artists can emphasize certain areas of their compositions, create a sense of volume and three-dimensionality, and evoke specific emotions in the viewer. The interplay between light and shadow can add drama, mystery, and intensity to an artwork, drawing the viewer's eye and enhancing the overall impact of the piece.