Usually with my students, I don't change anything on the embouchure unless something doesn't work. And even for the changing I keep in mind if we practice well, searching for the best sound, the best accuracy, the best intonation, flexibility etc, we will naturally find the way. So I usually don't do much on this matter, also because too much embouchure thinking can sometimes make people crazy.
What's your approach on that?
Michael Thompson's answer:
I agree wholeheartedly with your views on this question. What's more, I think you express them clearly and elegantly. Thank you.
I like to think of the embouchure as being nothing more than a flexible seal between the player and the mouthpiece. It's job is to respond instantly to changes in air pressure to stop the air blowing the seal and leaking. I encourage my students to think in terms of air speed; basically, fast and cold air in the high register and slower, warmer air in the lower register. I prefer to think of the embouchure as working on muscle memory; a kind of auto-pilot, which will do its job very well if you leave it alone. One of the biggest problems I encounter is students trying to make the high notes by squeezing the muscles around the lips but doing nothing much different with the air. If we increase the feeling of air speed, the muscles will need to respond, but that is precisely the point; they respond. They don't lead the way. One of the other things that causes big problems is the obsession with pressure as a bad thing. The great Philip Farkas cautioned against "excessive pressure" and I think we have largely ignored or misunderstood that. I prefer to use the word "contact" and treat it as a friend. As with most things, it's a question of balance; not too much for sure but equally not too little.