MICROPHONES
Buy the microphone that is best for your type of voice and take care of it. Not all microphones are created equal. A cheap microphone will sound cheap.
Choosing the Right Microphone
Use a microphones with a "cardioid" (heart shaped) or "super cardioid" pick up pattern of operation. This pattern is designed to amplify sounds only from around the head of the mike ("directional" microphones), so that they don’t emphasise the crowd noise. This design also helps to minimise feedback (the screeching you hear when a microphone is pointed at a loudspeaker).
Most callers use a "Dynamic" microphone, which means that it does not require an internal power source to give a good signal ("Electret" microphones require a battery to boost the signal). All modern square dancing sound systems will work fine with a dynamic microphone, but some will not work properly with an electret.
If you have either a very high pitched voice or a very deep voice, you may find it helpful to select a microphone with variable frequency settings. These microphones can be set to "roll off" the highs in shrill voices, or if you have a deep voice they can boost the highs, to make the sound more pleasant and/or clearer.
A good quality microphone will last for many years and will help to bring out the best in you. You should treat your microphone like your toothbrush; it is a personal thing.
How to Hold a Microphone
For the microphone to pick up a clear, undistorted sound, it must be held about one to three centimeters from your mouth. Hold the mike at a constant distance, so the volume of your voice doesn't keep changing. Try to keep the mike steady, and don't let it wave about.
Do not press the microphone up to your lips or chin, as this will obstruct your mouth and may cause distortion. If you are sounding muffled over the microphone, it may be that you are holding it too close to your mouth.
The hand that you hold the microphone with should be as far from your mouth as possible, so that the dancers can see your face (and not just part of it). Although you see Rock Singers holding the head of the microphone, it is not good for the clear sound needed for square dance calling.
The mike itself should be held at a 45-degree angle, and slightly to one side - once again, so as not to cover your face.
One last thing to remember: if you want to say something that is not intended for the whole audience, don't say it over the microphone.
Correct Microphone Technique

Do’s and Don’ts of Microphone Technique
DO hold the microphone steady
DO hold it at a short distance away from your mouth (about one inch)
DON'T wave the microphone around
DON'T press it into your chin
DON'T place the mike on your lips (don't swallow it!)
DON'T choke the microphone (don’t hold it at the tip)
DON'T say anything over the microphone that you might regret later