Most effective SAT prep for writing section?

<p>I really want a perfect SAT score, but I haven't been able to ace the writing section. I can consistently get 800's in reading and math, but not in writing. I usually get 3 or so of the harder writing questions wrong, but there is no distinct writing rule that I miss repeatedly. I can expect a 10 on the essay, maybe higher if it's a good topic. So I was just wandering what would be the most effective test prep book/method to be able to ace the writing section.</p>