A key to introspection is to focus on the rhythms of your breath: on its calmness or rapidity; on its force of flow; on the location of that flow in the nostrils; on each pause between the breaths; on the relative length of inhalation to exhalation (in sleep, for instance, exhalation is twice as long as inhalation). Your breathing is a reflection of your mental state. As you watch it, you will find yourself becoming inwardly calm, and your stillness, in turn, will deepen your introspection.
