Rocks are rarely if ever placed in straight lines or in symmetrical patterns. The most common arrangement is one or more groups of three rocks. One common triad arrangement has a tall vertical rock flanked by two smaller rocks, representing Buddha and his two attendants. Other basic combinations are a tall vertical rock with a reclining rock; a short vertical rock and a flat rock; and a triad of a tall vertical rock, a reclining rock and a flat rock. Other important principles are to choose rocks which vary in color, shape and size, to avoid rocks with bright colors which might distract the viewer, and make certain that the grains of rocks run in the same direction.