Traditionally in mindfulness meditation you use your breath initially as the object of concentration to collect and unify the mind. You typically stay with the experience of the breath as it touches the body in a single spot, such as the tip of the nose or the rise and fall of the chest, or the feeling of the breath in the whole body. When your mind starts wandering, the breath becomes your anchor to which you return in order to stabilize and focus your attention.

Phillip Moffitt