An interesting thread to follow and read about other people's experiences. Personally, I remember being scared to death teaching science to UK high school kids but I have to say that it is a very fast/steep learning curve. At first I found it difficult to control classes, too much teacher talk and the students become bored. 'Firm but fair' was the route that I eventually chose and it has served me well since. Treat the pupils as human beings but draw a line and stick to it regarding discipline. In Asia I find discipline issues to be much less common and this allows me to concentrate on good teaching rather than dealing with distractions.