You can't fake this music. You might be a great singer or a great musician but, in the need, that's got nothing to do with it. It's how you connect to the songs and to the history behind them.
So I write melodies - thirty, forty, fifty - then I cast them off until I have just two or three. If only one is needed, I go see the director and ask him to decide.
I prefer to sing in the shower because the acoustics make you sound great, baby.