What is the thought behind the snaps?

If you do lip slurs it is important that you feel and hear a 'click' from one note to the other. A good way to get this clickfeeling is to play the snaps. So the snaps are a 'soundbased trigger' for the right lipmovement. If the sound is good, the lipmovement is good. Some people asked me how I do the snaps and slurs, and to be honest, I haven't got a clue. I take care of my posture, breath in low and full, make sure my lips are set up right and then I play them. I am not aware of what the tongue does or what my air is doing. I think that whatever someone tells you, it's just a personal story of what this particular person feels and thinks he is doing. I suspect that everybody with good sounding (clicking, slotting) slurs does it the same way. I have no proof of that, but I do know that the snaps are a good way to get the right feeling.