There are three parts to a diaphragm or mouth call: the tape, the frame and the latex reed. The mouth call goes in tape end first and reed facing outward. Rest the call on your tongue and press it to the roof of your mouth to create a seal with your palate. Pushing air through the call causes the reeds to vibrate and produce those turkey sounds. Changing the pressure with your tongue and airflow changes the tone of the call. Once you practice getting sound out and holding tones, you can then begin practicing rhythm and cadence as that is the most important aspect of calling turkeys.