Are there some qualities or characteristics which can be seen in "Real" teachers? The answer to that is generally "yes", but those attributes may be different than what you expect them to be; and may or may not be shown, depending upon the qualities that the teacher needs to manifest in a certain situation.
Another question of some value is "Are there some general characteristics which show up in all real teaching settings?" A corollary to that question is "Are there some things you can generally expect to see in most situations with Real Teachings?" The answer to both these questions is "yes and no". Before we go into more detail here, it would be beneficial to consider how people become teachers, what kinds of teachers there are, and what they do.
First, I will say that most people who are considered as teachers or who consider themselves so, are not. They are not true spiritual teachers in a larger sense. For the sake of ease I will refer to them as "teachers" - with a small "t". There are some people who are Real Teachers. I will refer to them as "Teachers". There is also the larger Universal Teacher/Teaching. It is this that the Teacher becomes a part of and that expresses through the Teacher with the person aware. It expresses in other ways also without that specific personal awareness. This I will refer to as the TEACHER or TEACHING.
We find that the vast majority of people who are called a spiritual teacher, or who call themselves that, have a limited viewpoint through which to express limited information or experience. In general they work through structures which are dead or dying; cultish in function; and are either very misleading in the material that is presented, are severely curtailed in the capacity to reach toward the truth, or both. Within this category we also find the spiritual professional. He or she can be paid in money, power, fame, control, or any combination of the above - these being for the primary satisfaction of the person. (To read in-depth examples and discussion of teachers, teachings, and the ways in which people approach them, I would direct you to "Learning How to Learn", by Idries Shah.)
These people work in groups or organizations which at one time may have had real inspiration and/or a true source. They could be traditional religions, bastardized forms, splinter groups, cults, groups formed around personalities, or groups formed to espouse a certain belief, code of conduct, experience, method of seeking, effect or manifestation.
If the group was set up by one person without the proper training and authority, then that person generally sets himself or herself as that authority. He (I will refer to the person as "he" regardless of gender) may indicate that a greater unseen authority has anointed or appointed him as the earthly representative and invested him with authority.
For the one seeking guidance, it will be a test of faith. That one should be very careful to apply some of the criteria for the True Teacher that are found later in these writings - and compare them the best one can in both an outer sense, and by feeling and heart. The validity of this claim can generally be tested. Some of these are brought out in writings about the qualities and functions of the Teacher. They can also be verified or judged false by those who are Real Teachers directly. In the main, claims like this are false; but it should be noted that they CAN be true.
There are some situations where a person does have Divine Guidance and authority to bring forth a teaching. So in these - much fewer cases - it actually could be true, but one has to be very careful here. The person bringing this must have clear, unambiguous, impersonal guidance and direction for this; and must NOT in any case be driven by personal gain or greed. In the case of the Real Teacher, this person will also not have any individual desire or satisfaction from this position. If he is still seeking, looking for something, not in balance, has areas still to be assimilated, or is unsure; then he is "over his head"; and at the very least, is premature for this work.
More prevalent than the one personality driven group are groups which have deteriorated or never had a transmission. In this category, most of the people within it will receive some degree of instruction along with little actual direct spiritual experience and realization. The bulk of their instruction is intellectual. In cases where there is some broader experience, it is generally shallow and misinterpreted as to its value and applicability. However, at least it is experience instead of talk.
These persons, upon completion of a set of studies, are certified as teachers. They may be teachers in the sense that they can further instruct or convey information and shallow experience within the confines and structure of their field of study, but this is not spiritual teaching, and they are not Teachers. You will find, if you spend any length of time in their system, that the end is reached rather rapidly, and it is not universal.
There is another group of teachers. These are associated with real Teachings and may have as their source a spiritual Teacher with realization and transmission. As part of the learning process for his students, the Teacher may start (more properly assist) one along the path or work of teaching. It should be noted that this is a very tenuous situation. The Teacher must be extremely clear that indeed the student is to follow that path, rather than simply using him as an available vehicle to further his own work. There must be inspiration and guidance both for the Teacher and student to set one this way. It must also be understood that the student is not a Teacher in the real sense, even though he may take on some of the duties. That work tends to be more outer than inspirationally driven. The hope is that through this process the student will grow into a more full position. It is very important that the person be monitored closely to assure that the people he is working with are getting correct guidance. This person then starting out we can call a Teacher-in-Training.
In many cases you will come in contact with one or more of these people in the initial stages of contact with a group rather than the real Teacher. It is still difficult to evaluate the Teaching - if not impossible with traditional educational criteria - and this difficulty is compounded when the teaching goes through the very active and present filters of this student Teacher. (In fact, for a full evaluation you would generally need to either go through the teaching or have the perspective of the goal to really know it). You can hope, though, that he is trying to do his best by following his intuitive guidance and expression; and by adhering to the training, attunement, and transmission through his Teacher. You will find that in these situations, the Teaching may not be so limited as the previous grouping; and the end may be more universal and experience based, but that it is limited through the channel of the student Teacher and takes on the characteristics of his filter. You will have to deal with it on that basis.
When the student Teacher has progressed to a certain point, he is then many times given a title representing him as a Teacher. In reality this is generally just a starting position waiting to be fulfilled rather than the end of a prior instruction or course of study. It is like being given a name to grow into. But in this case, both the Teaching and Hierarchical Guidance accept and pass on the authority to this person to act in that capacity. The student Teacher should in the process also have gotten guidance and inspiration that he is to do this work and that this timing is now appropriate. It must also be added that if any of these criteria are missing, the student Teacher should not be elevated higher by an earthly Teacher, nor should he accept such a position if offered - no matter how tempting.
The final grouping we will now consider for the purposes of this writing is the real Teacher. He has gone through what amounts to all these previous stages and more - much more. It also should be noted here that this is not the end of the Teaching ladder; nor is it the end of the growth and learning of the Teacher. In reality, when a person really reaches this level he is also able to continue learning from that One TEACHER, as part of himself, and he as part of IT. From this perspective, ALL beings and things - including all people and nature - are sources of learning. They are welcomed, and appreciated as such.
The first thing to recognize is that this person is Real. The second thing is that he can show himself in many forms, but is always part of the same being. He must, if he has reached this position of function, have certain experiences common with those of a similar rank, and those who have come before or will come after. He may take the form of Guru, Sage, Murshid, or other un-named person, but in all cases re-presents the one true TEACHER. Depending upon his functions he will be readily seen - showing himself openly or hidden deeply, working as needs be.
This person will generally have gone through training and teaching by one or more Teachers; both on the physical and/or unseen levels. He will have been accepted by the Hierarchy and is recognized by others of his kind. He will be initiated in the greater path or ways, and will have attained and grown to the larger Universal path or Way.
He will be illumined and realize his true nature and being. He transcends the boundaries of space and time within himself. And he will know himself as one working unit. Within this framework and base, he will continue to grow, deepen in realization and function, and become more of what he is - without any worry, doubt, or inadequacy that there is more. And he will not want to be more - "want" to be a teacher. That is, he will not have personal desires to be a Teacher, rather than being one, and he will not have satisfaction and a feeling of accomplishment in his station. If he is not of this level as a minimum, then he is still a student Teacher - from the Universal point of view.
He may well be a teacher within a partial system, method, path, or tradition, however; and well capable of instructing a person within that more limited framework; or as a Teacher, if utilizing that path, tradition, or method as a framework, will also make clear the universality of the greater goal and function.
He will not claim to be a Teacher to justify function. Indeed, claims are meaningless. The real proof of a person is in his function, not his claims. The individual who claims to be a Teacher without first having both the background and experiences as indicated above - at a minimum as a base - is not worthy to be considered as such. All such claims are spurious, are false. This person is an imposter. The proof of the Teacher is in his works, and the proof of his transmission is found in his students - in their light and realization.