The Film Diva
posts this clever permutation on my "tell your story out loud" meme
Practice telling the story into a tape recorder like you are telling it to a member of your audience (e.g. if it's kid's movie, you're talking to a kid, if it's for young men, etc.) and then listen back. Usually if it's working, the listenng back part is great, if it's not, you will immediately scream for mercy, beg for release from your pain, and then once the slosh in your stomach has settled down, you'll narrow down the problems and get back to work.... :-)
I like this idea. While the feedback you get from yourself will be harsher sometimes -- God I hate my voice! I sound so stupid! Ugh, the bad part's coming up! -- it has the advantage that you can do it all by yourself. And we know writers are not the most social of animals. And humiliating yourself in front of yourself is much less scary than doing it in front of friends.