In playwriting, you've got to be able to write dialogue. And if you write enough of it and let it flow enough, you'll probably come across something that will give you a key as to structure. I think the process of writing a play is working back and forth between the moment and the whole. The moment and the whole, the fluidity of the dialogue and the necessity of a strict construction. Letting one predominate for a while and coming back and fixing it so that eventually what you do, like a pastry chef, is frost your mistakes, if you can.