You may have heard that you should use your diaphragm to sing, not your throat or your nose. This is true, but keep in mind that your diaphragm is an involuntary muscle and cannot be "used," only engaged.

To locate and enable the use of your diaphragm, follow this tip from Dr. Jesse Hopkins, head of the music department at Bridgewater College in Virginia: pant like a dog, or as if you've just run around the block. Pay attention to your breathing as you do this. The heaving sound you make is not what you're after, but the way you breathe is. When you are winded or when you pant, your diaphragm is the muscle you can feel contracting below your rib cage.

Hopkins also suggests having a friend monitor your breathing exercises at first, to ensure that you're doing it properly, like a spotter in gym class. Just try to pick someone you're comfortable with; you probably don't want your crush from math class to watch you panting. At least not on your first date...