In a recent blog post, Neil Gaiman discusses the topic of second drafts:
The second draft is where the fun is. In a first draft, you get to explode. The objective (at least for me) is to get it down on paper, somehow. Battle through the laziness and the not-enough-time and the this-is-rubbish and everything else, and just get it written. Whatever it takes. The second draft is where you go and gather together the fragments of the explosion and figure out what it is you did, and make it look like that was what you always meant to do.
The whole post is interesting (and he says more than the above snippet on the subject of second drafts). Also, it includes dancing bees; never a bad thing.