The I Ching is a heuristic device for understanding the rolling over of opposites in creation.
First we must understand that Yang is a celestial cause and Yin is a terrestrial response. All things are Yin and some things are considered Yang by analogy only. If you look into the meanings of these terms it is quite clear that Yang mean some invisible cause issuing from Heaven and impacting earth. But earth is made up of myriad opposites, and these opposites all reflect the more general relation between yin and yang that appears as causation, and so there is a ramification of the analogies of yin and yang throughout existence.
In a sense Yin and Yang are like variables and given a level of permutation of a progressive bisection one may substitute any opposites from the myriad opposites in creation for yin or yang. Thus the first step is to consider your situation, whatever it is at the moment that you want to understand, and pick out the most important and dynamic opposites that are affecting your situation. Then what you do is you rank these from the most important to the least important. Best to pick out at least six opposites that are affective in your situation.
Next step is that you decide of these opposites which is yin and which is yang elements from each opposites. This is not easy, because by analogy it is not always intuitively obvious which is the Yang or driving or causal side of the opposition in a given case. But you must remember that the true yang element is an invisible cause that is hitting the situation from an unknown direction, and that the opposites you pick are only being moved by that invisible cause, so that all the pairs of opposites are yin with respect to the invisible cause descending from heaven to earth. However, in each situation there is one of the elements from each pair of opposite which is the more dynamic, and that is considered yang in each case.
Now once you have your six pairs of opposites and you have decided which elements of each pair are yin and which are yang, then you do the divination using the I Ching to determine what the starting hexagram for the situation, and what the ending or transformed hexagram is. You should use the I Ching that was found in the grave site more recently than the traditional I Ching as your first reference because it is more original. But they are similar enough that referring to the handed down version does not matter. Pick a good scholarly translation though, there are some pretty strange translations that are available.
Line up the first hexagram you get with the list of opposites that you have chosen to represent the situation you are in. Then read the I Ching commentary against that set of opposites. Then note the changed lines, and note the meaning of the transformed hexagram, in relation to the changes in the meaning between the two hexagrams. When you look at the changed hexagram you are looking at a possible permutation of the given situation into a different situation. This is not a prediction but indicates a propensity or tendency in the situation that your unconscious has thrown up to you as a state you have accessed in the divination process. Nothing is telling you the future, the tendency or propensity is in the current situation you are in and that you are wandering about.
But the secret of the I Ching is that it is like a house of mirrors in which each pair of Hexagrams are separated by another hexagram by which one hexagram, the situational one, and the other hexagram the propensity or tendency are separated from each other by an orthogonal hexagram. Work out what the orthogonal hexagram and that will tell you the barrier between the current situation and the psychoidal propensity that your unconscious has thrown up to you through chance. That hexagram represents the transformational value of the potential in relation to the current situation. Your read all three of these hexagrams in relation to the opposites you chose before generating any hexagrams, and what it is telling you is in a given situation what the likely path of the rolling over of opposites might be. So if you are in Hexagram H1 and your propensity is toward H2 but the traversed mirror between the beginning and end is hexagram is H3, then you will get some inkling of the potential transformation in the situation that you are considering.
Look at what the Great man would do in these various hexagrams and consider your approach to them based on what he would do. The hexagrams are a mirror for you in which you can see your own relation to the world. It is a mirror because it contains all the possible transformations. Whatever the rolling over of the opposites will be it will come from the transformations of the opposites you have picked out and aligned with the hexagrams, against which you are interpreting the hexagrams. By looking at a possible potential for change in the situation, your are prompted to consider the actual potential for change in the situation. By looking at the door way between the current situation and the potential transformation of that situation, you see the limitations on your movement in the situation.
If you use the I Ching as a guide for looking deeper into the situation you are in and its potential for transformation by the rolling over of opposites then it is hard to go wrong. If you think it is going to tell you what is going to happen then you are lost anyway, and there is not much that can be done for you, you will misread the situation and you will fail to understand what the oracle is indicating. But if you align the oracle with the dynamic opposites in the situation you are in, and you use the hexagrams as indicating aspects of the current situation and its propensity for self-transformation by the rolling over of the objects, then you may learn something about yourself that you did not know before. Whatever is thrown up to you from your look at the situation based on the I Ching, is merely a reflection of the mandala of your greater self-mirrored in the world. The I Ching is the mirror of that self because it contains all the possible permutations of the progressive bisection at the level 2^6 which is at a fairly high level of complexity. The opposites you identify in the situation will roll over into their opposites or jump to another state within the set of hexagrams in the next moment, then there will be a new propensity for that moment and a new mirroring by the transforming hexagram. Pick significant moments to take samples of this flux of existence. The I Ching is a model of the interpenetration of existence with itself, and you with it. When you look out at the opposites that are controlling the situation at the moment you are looking at a mirroring of your self in the mirror of existence in which you are completely immersed. The I Ching is merely a heuristic device to remind you of that mirroring. Look in the mirror occasionally to see if your tie is straight but avoid becoming narcissistic.
In effect if you read the opposites of creation and the rolling over of the opposite in creation directly then you do not need this heuristic, it is a crutch for the beginner to aid their learning about the rolling over of opposites in creation, or the sudden transformations of things into their opposite. Watching for the dynamic in the situation (the landscape’s self-transformation) is more important than consulting the map of the landscape (the I Ching). It is only telling you what you should already know, existence interpenetrates and you are not separate from that interpenetration.
In any given situation there is always some dynamic invisible cause at work, and the scattering of the opposites in creation indicates that dynamic. Look beyond the dynamic of the opposites to what make them turn and shift and that is where the heart of the matter lies.