The Posture of the Breath
Like thoughts, the breath comes and goes. If anger arises, the breath becomes angry. If sadness arises, the breath sighs. If your practice is tense, the breath is tense. Attend to the rising and falling movements of the lower belly as the breath fills and releases. Each breath is fresh, new - you have never breathed this breath before. The breath is a touchstone through which you can bring body and mind together in the same time: here, now.
Just feeling the breath itself, abandon notions of the breath. Don't even "watch" or "follow" the breathing. Just feel this breath. When you wander into discursiveness and get lost in thoughts, return to just this breath. When mindfulness darkens or sinks, return to just this breath. Practice free from struggle. Don't tense the belly around the breath to make sure you are watching it and thus take on the stance of a "watcher". Don't try to manufacture deep, calm breaths. Just breathe as you breathe. With this breath, you enter into your life.
The breath is a mirror of the mind.
In this posture of breath, just sit.