The right approach to teaching and learning?

One of those nights... Went to bed to early I guess, so I happened to wake up and.. started to think! ;)
At times I question myself as a singing teacher. Am I going in the right direction? Is there something I am missing? Something I could improve?
Sure it is. Many. But specifically, couldn't I use, as many others do, personal sensation to explain how singing works?
Don't get me wrong, at times, sporadically, I do. But grounding own's teaching only on these kind of things... No, I don't think I could get down that path, as fascinating as it is.
In my experience, and as far I as know, it's like chasing a shadow, an image reflexed on the surface of the water. As soon as you touch it, it changes, vanishes away.
No. Personal sensations are what they are: personal, they belong to the individual. And, yes, you can be sure that when that note is right you feel something good, but from the moment you translate that you are interpreting it, and more that often one would want, confusing the cause with the result. From the moment you look to reproduce that sensation alone, you forget that to arrive at that sensation you must have put something else into place, or it would have never manifested itself. So you are now in a sort of labirinth, and the more you move around you loose the sense of direction, the sense of reality, of where you came from.
What you do need to know is how you got there and got that feeling. That feeling good sensation, whatever it may be the mental image that comes out of it, comes from something else, from a coordinated use of different parts of your body, and sure as death if you haven't got that coordination right, that feeling will not be there when you need it. SOMETHING has changed. Will you try to reproduce it? It does not appear. What do you do, now?
No, I don't think I will sacrifice my knowlegde of how one's body works in singing, gained with much study, as related to physiology, acoustics, phisics, and... common sense! You don't need to be a specialist, but a general grounding in these disciplines gives you an insight into what goes on when singing, what must be present, what must not be; moreover, it equips you with the ability to pass informations on to the student without having to be mystical or having to create a new terminology, applicable from you only, to what can be expressed in a much more common and accesible fashion.
...
But there is definitely one thing (amongst things like my piano playing..?) I need to improve: I need to understand that some students can get quite discouraged when continuosly told that the sound is not right... They may not have my standard. And their standard is different because the very level of understanding of their own voice doesn't allow for it to be! It could not be otherwise.. If they knew, they would immediately do something about it.
This unacceptancy is probably excessive for some. But those who understand that is is dictated by a a fair reason, and are willing enough to explore it, those are the ones that make greater progress. For the very reason why that sound is not right causes also troubles when approaching other aspects of singing, for example that difficulty at keeping in pitch in certain areas of the voice; or the slowness to move the voice when singing fast passages; or again the shortage of breath... or the strain in reaching those high notes!!
I need to balance my desire to give them all an quickly with the knowledge that also slowly things can be grasped and improved. After all they are not going to sing for an opening night at the opera house. And even if so, they just want to have fun on the way.
:)