Here are a couple more insights from Christine Vachon's book about independent film-making, "A Killer Life":
"I think it usually takes three drafts for a script to get there. The first draft of a screenplay has energy. The second draft, by trying to fix all the problems of the first draft, tends to be a muddle. The third draft corrects the overcorrection and hopefully improves what works in the first place."
"We have a saying at Killer [Films]: it’s not the length that’s the problem, it’s the perception of length. A short film can feel long when motivations aren’t clear, transitions don’t match, or the proportions of the story are off. It doesn’t matter if your movie is ninety minutes. If people feel like it’s two hours, then you’ve got to fix something."