If you use chalk on the rock, brush it off when you are done. If you use tick marks, brush them off when you are done. Wipe your feet off prior to each climbing attempt. Excess chalk and any dirt, leaves, or mud can polish holds over time. Do not drag your pad from one climb to the next (in order to minimize erosion). And most importantly, Leave No Trace. Pick up your trash and place it in the trash cans at the trail head.