I. Nonconceptual meditation. Zen. Cutting off all thoughts and mental imagery and relaxing into the unnameable and infinite. "Nothingness" -- we call it "Mu" because any positive word or label would only create some sort of emotion or mental image. By calling it "Nothingness" we cut off all attempts to "define" it and simply sink into the life-giving experience of the Original Self, the Ancient Ancestor.
But in Zen/Dhyana we do not even "know" it since the awareness of doing Zen disappears. Self and universe are both forgotten, yet this is not the end. "Cast away all things, become without thought and without mind" -- yet, inevitably, thought, mind, and the entire so-called universe return with a keen sense of "I-awareness" and "I-aliveness."
As Dogen wrote, "When no phenomena occur inside me there are no buddhist teachings, no buddhas, no self, no other, no universe, no suffering, no nirvana; when phenomena occur inside me, all the rest reappear in an instant."
Yet, when it all returns, is it not mysteriously refreshed -- are not colors, sounds, and textures now impossibly clear and vivid, as if sparkling with the original dark luminosity? Looking up at the drifting white clouds, does one not see one's own great Dharma body?
II. Ki training. "Exhale to the limits of the universe; inhale to the infinitesimal zero point in the Hara." Extend energy into one's environment and refine and integrate the "one perception" into everyday living. "The formless flower of samadhi" in action.
III. Direct inquiry. Self-searching "Awareness" experiments aimed at Kensho -- instantly realizing the Juin Gong, the True Self.