See here the whole process of manufacturing the Shofar.
When blowing the Shofar, we should not place it into our mouth, between the lips, the way we inflate a balloon. The Shofar must be placed against the closed lips, usually on one side of the mouth (most people use their right side) or in the center of the mouth. Then you should blow air with your lips tightly closed. Buzzing the sound of the letter ‘P’ while vibrating your lips, as you release the air.
You should not inflate your cheeks or force your lungs. You should be breathing as normally as possible. The most challenging aspect of this technique is to adjust the Shofar’s mouthpiece against the lips in the right angle, preventing air from escaping from any other point of the mouth.
THE VOICES of THE SHOFAR (qolot)
The Shofar normally produces one single “musical note”. During Rosh haShana we blow this note with three different “voices”. The first voice is called “teqi’a”. The “teqi’a” is a long, single, uninterrupted sound. Then we have “shebarim”, a broken voice, dividing the sound into three shorter voices, interrupting the airflow with the tongue. And finally we have the “teru’a”, consisting of a rapid series of nine or more very short sounds.
Watch in this video (between 06 to 09 seconds) the way the Teru’a sound in most Jewish communities (tapping the Shofar’s mouthpiece with the tip of the tongue).
According to other traditions, teru’a is more like a wave of short sounds. This is the way teru’a sounds in all Yemenite and many Syrian Jewish communities.
The typical combination of sounds on Rosh haShana is the following:
teqi’a / shebarim-teru’a / teqi’a (4 sounds).
teqi’a / shebarim / teqi’a (3 sounds)
teqi’a / teru’a / teqi’a (3 sounds)
As you can see, this series consist of ten sounds. And it is repeated ten times during Rosh haShana. Three times before Musaf, three times during Musaf, three times during the repetition of Musaf and one time after Musaf.