Stand in front of a full-length mirror and hold yourself as if you were about to sing. Your legs must be shoulder-width apart and your shoulders must be relaxed and slightly back. Your neck must be long and straight without any constriction, your jaw slightly loose and your face relaxed. Watch for any signs of misalignment in the mirror; your body should be straight.
Breath from the diaphragm and pull your air into the pit of your stomach. The diaphragm muscles will help you to take a large breath, which will support your voice. If you have trouble breathing with your diaphragm, pretend you are yawning; this process uses the same stomach muscles.
Warm up by singing a scale in the middle of your range. Sing the entire scale and attempt to get a good sound on each note. If you can't sing a scale, sing a single note and hold it out for four beats. Then sing another note that is slightly lower and return to the original note. Complete this exercise five times.
Sing music that falls only in your vocal range. Avoid singing music that is too high or too low. This will place added pressure on your vocal folds and make it difficult to sing.