Do this: Place your thumb and index finger on the back of your hand. Press down and pull the hands apart as should you are stretching the outside of the back of your hand from among those two arms. Now, put the clarinet mouthpiece to your mouth, anchor your lower lip with the reed, close
the mouth off across the mouthpiece and flatten or point the chin. If you are flattening
precisely, the skin among your lower lip and chin should stretch or “firm up” like the skin on the back of your hand stretched by the arms. Clarinet is held too high. This angle of clarinet impacts embouchure poorly.