Listen carefully to first criticisms made of your work. Note just what it is about your work that critics don't like - then cultivate it. That's the only part of your work that's individual and worth keeping.
It's no use to go and take courses in playwriting any more than it's much use taking courses in acting. Better play to a bad matinee in Hull - it will teach you much more than a year of careful instruction. Come to think of it, I never did play to a good matinee in Hull . . .
The mission of the playwright is to look in his heart and write, to write whatever concerns him at the moment; to write with passion and conviction. Of course the measure of the man will be the measure of the play.
Most playwrights go wrong on the fifth word. When you start a play and you type 'Act one, scene one,' your writing is every bit as good as Arthur Miller or Eugene O'Neill or anyone. It's that fifth word where amateurs start to go wrong.