Not sure what the two books you've looked through are, but have you tried "Peterson's perfect personal statements : law, business, medical, graduate school"? It helped a lot of my friends (who are already in professional schools) and me when writing the personal statement. The content is really up to you in terms of what you want to present to admissions, but the book helped me with organization (which I think is super important) and a bunch of other things.
The content itself, however, is a whole different story... as you've probably heard one too many times.
Oh yeah I agree with alenadoma, get several people to read over it. I went to the writing center WAY too often (but they were my peers), a friend in professional school, and a professor to read over it. All of the STUDENTS told me the same thing, that it was great, the friend gave me a little bit of constructive criticism because she works in the admissions office at her school, and my professor almost tore apart my PS (but in a good way). It really helped to get different perspectives on it.