Thoughts are the image/manifestation of the always evolving psyche. So, by controlling them we can guide that evolution. This can be helpful for intense method acting as well as self-guided adaptation of the personality to the environment.
-Sit in the six-point position.
-Relax and let your mind wander into a state of thought.
-You will notice that your thoughts are random and compulsive. This is how you actually think: randomly. The goal is to control your thoughs to train your mind.
-Stay in control of your thoughts, controlling thier "flow" or progression, resisting random thoughts.
-After doing this first step once or a few times, do it again but now staying on one subject. -Analyze your experience.
This meditation is good for clearing the mind permanently, increasing focus and even intelligence. This is also and excellent tool to use for plotting and keeping the Sith mentality.