Even though your practice gradually matures, there are as many potential pitfalls in your practice as there are many hazards in the cliff before withered trees. It is necessary to elucidate them in detail. The pitfalls can be recognized only when you have personally gotten that far. Now is the time to talk about them.
My school differs from the Zen/Chan school in that it has confirmatory signs for each step of the way. Let us first talk about the differences and then the signs of verification. When you are going to practice this, first see to it that you don’t have much on your mind, so that the mind can be alert and free. Make your mind comfortable and your energy harmonious, then enter into quietude.
In this quiet state, it is essential to get to know the opening and working of the aperture. Don’t sit inside nothingness or indifference (aka Emptiness of Indifference). As you let go of all entanglements, you become alert and self-composed. But don’t get too concerned about attaining the goal either, nor be too eager about making progress. Those who take it too seriously tend to have this problem. It does not mean that you shouldn’t be dedicated and diligent, but verification/validation shows up between existence and nonexistence. The key is to focus without focus.
Now in the midst of alertness, relax. But don’t fall into the ensnaring world, where the five kinds of yin demons take charge. When you are meditating, if your state is closer to dry wood and dead ashes, and lacking the yang energy of growth and creativity, then it means you are ensnared in the world of yin. Your energy is cold, your breathing is coarse, and you have a number of other chilling and withering experiences. If you continue this way for long, you will degenerate.
Nor must you be led astray and go along with all objects. This happens if, after you have acquired a quiet state, a train of thoughts with all sorts of loose ends suddenly appears for no reason. You find you cannot turn them away, and you even feel comfortable going along with them. This means the master is enslaved by the servant. If you continue this way for long, you fall into the realm of forms and desires.
At best one reincarnates as human, at worst one reincarnates into the animal realm. Once you know this, you can seek experiential proofs. For instance, a fox may be able to roam in the great mountains enjoying the wind, the moon, the flowers and fruits, and taking his pleasure in coral trees and jeweled grass. But after three to five hundred years, or thousands of ages, his reward is over and he will be born again into the six states of existence. All of these are wrong paths. Once you know the wrong paths, you can then look for signs of liberation.