Sit in a chair and place a clock with a second hand on the table. Follow the second hand with your eyes as it goes around. Keep this up for five minutes, thinking of nothing else but the second hand, This is a very good exercise when you only have a few minutes to spare, if you are able to keep every other thought in the stream of consciousness subordinate to it. As there is little that is particularly interesting about the second hand, it is hard to do this, but in the extra effort of will power required to make it successful lies its value. Always try to keep as still as possible during these exercises.
In this way you can gain control over nerves and this quieting effect is very good for them.