Hey Guys,
I don't know which programs you're trying for, but I most definitely feel your personal statement pain. It was the toughest piece of my USC app last fall. Let me tell you a few things I wish somebody had told me.
1. Figure out what your application is doing in front of them. Come up with two or three d@mn good reasons why you belong at USC and make them the soul of your statement.
2. Just do it, then do it again (repeat as necessary). Be aware that it's not easy and it's not meant to be. Force yourself to get something down, go over what works, then do it again until you're happy with it.
3. Imagine yourself as a character, then tell them your story. You want them to get to know you, and hopefully to like you, so pitch yourself accordingly. If you were a protagonist, what personal qualities would you highlight? How did those things contribute to you arriving on their doorstep?
4. At the end of the day, they are looking for alumni. Your success is their success, so do everything you can to present yourself as a good bet. Have you visited? Why do you think you're a perfect fit? Be confident (though not arrogant!) and demonstrate your vision and your enthusiasm.
5. Humor is an option. My statement began with a hilarious anecdote from my days as a medical office assistant. It probably told them more about me than any bumbling attempt to summarize myself, and it set up a flow for the rest of the piece. More to the point, humor amid a sea of seriousness will make your statement readable and memorable.
6. You'll know it when you've got it. 'Nuff said.
I hope this helps, and didn't come off as overly professorial. Good luck!