Sit up straight and use proper posture to ensure that your body is free of tension and you are achieving the best sound possible on the clarinet. Relax your jaw slightly, keep your throat long and open and sit with your shoulders slightly back.
Bend pitches between the range of G below middle C and G just above middle C by sliding your finger over the tone hole while playing a specific pitch. Partially covering a tone hole will make it possible to change the frequency of the pitch slightly, resulting in a bend. This technique also works for pitches above the D one octave above middle C.
Drop the lower jaw to release some tension on the reed. The pitch can be changed slightly and bent downward by using this technique. Be careful to keep the airflow constant.