The single highest "practice" common to Zen, Mahamudra, Dzogchen, Advaita and Kashmiri Shaivism is to free yourself from the conceptually elaborating process of "thinking" (projecting, remembering, scheming) &c. that implicates your Body of Reality is all sorts of false hopes, desires and fears. To succeed in this is to taste reality, to experience buddhahood here-now. That's why it is the supreme yoga, Atiyoga (Nisarga Yoga). Beyond this yoga there is only Sahaja, which is not a yoga but natural responsiveness to all situations free of any conceptual elaboration. So, there is "freeing yourself" and then there is "being free." The first is a yoga, the second is just the natural state.
Of course in Kashmir Shaivism there is anupaya, which is not a process at all nor a yoga but just being suddenly initiated into Reality. This can happen if a Guru crosses your path and you happen to have the right potential. There are some Zen stories about such happenings. It can also just happen for no reason, when you are swimming in the summer sea.
Whether it happens spontaneously or you have to do some some yoga to go beyond, this realization projects you from falsehood and confusion into the natural enlightened state.
What is the natural state? How may I describe it to you? Let's say I am lying on the porch looking up at the white clouds, and hearing wind chimes clamor nearby. If I am in the sahaja state, there is absolutely no feeling of inhibition by thinking, no withdrawing of my perceiving mind from the instantaneous reception of sights and sounds, no conceiving of a relative past, a present or a future. In this "state free of conceptual elaboration" I experience joy and bliss because I am the being of pure awareness. I am the vibration of pure consciousness, not subject or object. But if I do feel in "myself" some fear, displacement, reluctance, shying away from this clear and radiant isness -- if I feel the intrusion of conceptualizing and its emotional baggage-train -- then I must do some yoga by consciously not holding onto the arising and sinking of mental formations. In Zen this is called using one thought to annihilate all thoughts. In Taoism it is "sitting and forgetting," and also "fixing contemplation." After that, you drop even the one thought. The one thought is also the "one point" focus of yoga training that calms all mental activity and culminates in samadhi, bare and naked. There are many subtleties to it and different ways have been taught, but the goal is always the same.
What's the goal of the highest yoga? Nothing but ease and bliss -- the natural state. I lie under the sky laughing. There is no sense of any sensation as being an "outside" opposed to my "inside" of self. In pure awareness there is only a nondual experiencing that does not leave any tracks. I am neither behind sensations nor ahead of them, neither inside nor outside, nor somewhere in between. "I" am really only this naked capacity for experiencing it all in its sheer brilliance, and this "I" isn't inside my head, nor is it anything apart from the brilliance of the experiencing, nor does it fragment the experiencing into this or that "part" or "object" that gets experienced and processed conceptually. Rising on the wave I am the wave itself and the water it is made of. What's the problem? Can you set up fences in the empty sky? It's all just "this" and has never been otherwise. Such is the intuitive realization of Reality. These words just point to it, they should not be taken for It.
Even after you have tasted reality, lived in the blissful natural state, there may still be some "thinking-emotional" obstacles remaining for you, and you may have to do some special yoga to get rid of them. This will become clear in time. Of course, in the absolute there is no time, so as long as you are fully "it" then there can be no problem. Typically the problems start up again when you leave the timeless state and begin interacting with people. If you feel some resentments or bad feelings begin to flow, cut them off. You do this by cutting off thinking about them one way or the other, so that your interactions self-liberate as just the spontaneous activity of Reality. That's the best way but there are other approaches that are more complicated, like the Tibetan approach of paying reverence to everybody, even your detractors and critics, because you recognize them as having been your mother in a past life. Such a technique raises thoughts about past lives, the objective nature of things and so forth, so it can create more obstacles in the end. After all, whether or not a person was your mother in a past life, that person is still -- although maybe unknown to him or herself -- the spontaneous appearing of Reality right now, and Reality is the mother of everything, so what's the problem? "Two stalks crooked, three stalks straight."
Master Pai Chang, who was the teacher of the Zen Master Huang-Po, said that if you make your mind like space your practice will be successful. This is really the only practice, the only yoga -- make your mind like space. Space contains everything. Every so called object appears in space yet it does not leave tracks in space. Here we are speaking of an absolute space, not the space of modern physics. It is just that clear no-thing in which everything appears, just as the surface of a mirror is where all reflections appear, and looking at the mirror you never see its surface, only the images. And how are things different than this space, and how is the mirror surface other than the images you see in it? It's all just That. Is this realization the end point of yoga? It may be the end point of yoga, but it is only the beginning of the art of living.
You might raise the objection that I am talking about annihilating selfhood, individuality, everything that seems to make sense of life and make you you, and that this is a frightening idea and practicing like this might lead to madness. I will only retort that the stress of going around mistaking your Body of Reality for all these mental objects and thoughts and saying "I want this, I don't want that" is extremely frightening and has unpleasant effects on the body in the form of stress. Only if you consider your mentally imagined "self" something real will you get scared of losing it. But you don't have such a self, and what you are goes far beyond what you think or imagine. Do you worry that when you wake up from a dream the person you are in the dream will be annihilated? Not at all. The one who is the source of all dreams is always closer to you than your eyebrows and nostrils. To be liberated is to be free of all senseless ideas "about" Reality so that you can live it with some bright vigor, lively as a fish jumping. Why live an impoverished existence as a slave to ideas? Wake up to the soundless thunderclap of Isness!
Here are some poems for you to illuminate the inconceivable natural state:
starry sky expanse flashes of heat-lightning
bare & clean without a mark the ancestral home
mountains & rivers the pure ringing of stillness
a day in the heat sound of a bamboo rake
a water buffalo walking in green water dips his head
shining reflections the subtle whir of dragonflies