Breathe in deeply from your diaphragm by expanding your sides and stomach. Feel your stomach, sides and back expand with air.
Sing the C above middle C if you are a woman, or an octave lower if you are a man. C on the piano can be located by finding the white key to the left of the set of double black keys on the piano. Middle C is the C that is closest to the center of the piano.
Descend chromatically, while singing every note, a total of seven half steps. If done correctly, you will end on the pitch F. On the piano this is the white key to the left of the set of triple black keys. Ascend back to the original note C.
Sing the same sequence, starting a half step lower. The distance between two adjacent keys on the piano, whether black or white, is a half step. This time you will end on the pitch E, which is the white key to the right of the double set of black keys. Ascend again singing all the notes until arriving at the original note B.
Extend your range downward by continuing the sequence down by a half step each time until you can sing no lower.