Although it has been around for some years I have only just discovered that hilarious training manual: The Art of Coarse Acting or How to Wreck an Amateur Dramatic Society by Michael Green. The 1994 reprint is published by Samuel French. You can get it from Amazon for £8.25.
Coarse actors, of course, are bad actors and those, sadly, are not exclusive to amateur theatre. ‘A skilled actor can make a piece of wood seem like a sword. A coarse actor can make a sword seem like a piece of wood’ asserts Green. And we’ve all seen it just as we all know the small-role actor who is hammily determined to be noticed at all costs, the one who never knows his words, the prompt who falls asleep, the actor who insists that the audience never noticed a thing and all the rest of them.