Do this: Place your thumb and index finger on the back of your hand. Press down and pull the fingers apart as when you are stretching the surface of the back of your hand from between 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're flattening as it should be, the surface among your lower lip and chin should stretch or “firm up” like the skin on the back of your hand stretched by the palms. Clarinet is held too high. This angle of clarinet affects embouchure poorly. Between a 30 and 40 degree angle is usually accepted as correct. You can test this by listening for your sound as you progress the clarinet around. Try this: set your embouchure, move the bell of the clarinet too high. Blow. As you're blowing, slowly bring the clarinet bell down toward your body.