You can create an L composition by placing a vertical mass on one side of you rendering and balancing it with an open area or distance on the other side and a horizontal base at the bottom. This dramatic and solid composition firmly anchors your subject on two sides of the rendering space, thus drawing the attention of the viewer both vertically and horizontally. The open area in this composition can provide a great frame for your focal point, Or you can chose to make your focal point the vertical mass of the L,  which the artist has done in the image above.