Postbox letter from Brian
If you have any hand in employing teachers, and you're only interested in warm bodies in the classroom and paying the very least, you're going to attract the worst kind. But if you actually take the time to read cover letters, read CV's and try to get a feel for the person applying, your life will be so much easier.
Postbox letter from Martin
To keep teachers longer will be hard. The demand of good teachers is high and many native English teachers will go to international schools. Even good non-native speakers go to international schools. What is left are many teachers, but nowhere near enough to fill schools with middle-class children.