One's way of breathing is one's way of Being. To do Ki breathing one should "allow one's outbreath to flow out naturally, and one's inbreath to enter the body freely." Also, "exhale so as to reach the far ends of the universe, and inhale so as to concentrate breath infinitesimally in the Hara."
Ki/Musoku breathing, or "the breathing that transcends breath," entails the loss of any particular sense of self and absorption into "the formless Ki of the universal." Koichi Tohei Sensei describes how to attain this way of breathing here.