Vipassana Meditation

Vipassana meditation is a Buddhist practice that uses pure self-observation to realize the transient nature of life's activities.
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If you do find yourself thinking . . . then silently label it "thinking" and go back to the breath. If you hear a noise -- a cough or a siren on the street, for example -- label the noise "cough" or "siren" and return to your outbreath. If you feel discomfort in your ankles or knees, label it "pain," adjust your position if necessary, and return to the breath.

Related to this is the yoga meditation, witnessing your thoughts.