We call the heart of the formal mediation practice “sitting meditation” or simply “sitting”.
As with breathing, sitting is not foreign to anyone. We all sit; nothing special about that. But mindful sitting is different from ordinary sitting in the same way that mindful breathing is different from ordinary breathing. The difference is your awareness.
To practice sitting, we make a special time and place for non-doing, a time for simply being. We consciously adopt an alert and relaxed body posture so that we can feel relatively comfortable without moving, and then we reside with calm acceptance in the present without trying to fill it with anything. You have already engaged in this in the various meditations in which you have watched your breathing.
It helps a lot to adopt an erect and dignified posture, with your head, neck and back aligned vertically. This allows the breath to flow most easily. It is also the physical counterpart of the inner attitudes of self-reliance, self-acceptance and alert attention that we are cultivating.
We usually practice the sitting meditation either on a chair or on the floor. Whether you choose the floor or a chair, posture is very important in meditation practice. It can be an outward support in cultivating an inner attitude of dignity, patience and self-acceptance. The main points to keep in mind about your posture are to try to keep the back, neck and head aligned in the vertical, to relax the shoulders and to do something comfortable with your hands.
When we have assumed the posture that we have selected, we bring our attention to our breathing. We feel it come in; we feel it go out. We dwell in the present, moment-by-moment, breath-by-breath. It sounds simple, but it’s not necessarily easy. Full awareness of the in-breath, full awareness of the out-breath. Letting the breathing just happen. Observing it. Feeling all of the sensations, gross and subtle, associated with it.