What are the control exercises in the Stoic method?
All the classical Stoics agreed everyone has three degrees of control over their lives: complete control, some control, no control. This is the essence of the Control exercise.
In every decision you make everyday, the first question to ask yourself is how much control do I have over this situation. Every time you are confronted with a problem, a crisis, a physical or psychological assault, the degree of control should influence your approach to its resolution.
Epictetus was probably the most extreme in teaching his students that we have no control over anything except the will. The right use of will, he would say, is completely under our control. No one, not even a god, can take that away from you. The choice to build a noble character is yours and yours alone. All else is left to fate.
We know that there are some things over which we do exercise some control. If you are looking for a wife or husband, how you go about finding one will have some control over the outcome. If you stay at home night after night and wait for the right person to knock on your door your chances of finding that person are considerably less than if you actively go out and make yourself available in social settings reflecting your personality.
We also know that we are all mortal and there's little we can do about death as the final outcome, nothing actually, no control, but we can have some control over our health and longevity by taking good care of our bodies while we still live. The most important aspect of this exercise is the tranquility that comes from realizing that many of the things we fuss and fret about are largely out of our control. Someone cut us off in traffic, is there anything we can do about it? Of course. We can speed up and shoot the jerk, but that's not going to prevent another rude person from cutting us off in traffic in the future.
As Marcus Aurelius says people will have bad breath, because that's the sort of odor that emanates from such places. Why get annoyed? Leave it alone.