One of the challenges in teaching and learning modern/colloquial Tibetan is that there seems to be no standardised orthography. For those whose mother tongue is Tibetan, there has been no need to learn modern/colloquial Tibetan. Modern/colloquial Tibetan grammar came to be written for the first time for non-Tibetans and mostly by those who had either no philological training or interest. The result is a heap of textbooks with all kinds of orthography.
I have two suggestions to make, which are predestined to fall on deaf ears. First, even Tibetan school children should perhaps learn grammar of modern/colloquial Tibetan just as school children in England or Germany learn English or German. Second, as a measure to standardise the orthographies of modern/colloquial Tibetan, an attempt should be made to resort to only those orthographies that are attested in classical or literary sources. I believe that in most cases, we are bound to find precedence cases in literary sources. This would lead to the refinement and standardisation of both levels of the Tibetan language.
Let me give one example for my second point. Anyone teaching modern/colloquial Tibetan would realise the auxiliary verb yod (pa) red has been spelt in various ways: yod red (I used this!), yo’o red (following the pronunciation), and yog red. The orthography yog red seems justified if we consider the occurrence of yog in some old Tibetan writings with the meaning of yod/mchis (gNa’ rtsom, p. 402). I have been arguing that although the correctness of pronunciation is crucial in modern/colloquial Tibetan, one cannot disregard the orthography. By doing so one would destroy a language. (By the way, I am not at all happy the way rDzong-kha orthography has been treated by my fellow Bhutanese at home.) If the orthography and pronunciation tally, it is all the better. If, however, the orthography and pronunciation of a certain word clash, I would suggest that the orthography should have the precedence over the pronunciation. Even in other languages such as English (and perhaps also French), children learn received pronunciation (RP) of many words from their parents and teachers and you do not start simplifying all the orthographies just because they are not spelt, as they should be pronounced.
It is, of course, clear that we should not make things more difficult or simpler than it is necessary. The tendency to simplify orthographies, grammar, and language itself, mistaking for pedagogical or didactic skills, is, in my view, appalling. It would ultimately destroy a language. Having said that, I believe that the real pedagogical or didactic skill lies in making students learn a difficult and complex language with ease and pleasure.