2. Make excuses _ Lots of applicants have weaknesses in their application files, especially in their transcripts. Maybe you got low grades your freshman year. Maybe you had to leave school and work for a while. Maybe you got an F in that statistics class and had to retake it. Or maybe you got a degree in one field and are applying to grad school in a different field; or you didn't pass your medical residency exams the first time. Whatever your weakness is, do not offer excuses and do not bad_mouth anyone. So it wasn't your fault that the professor lost your final exam and flunked you, or jobs dried up in your original field of study, or you had the flu when you took the GRE. Don't say anything that sounds like an excuse or sounds like you are blaming someone else for you failing to achieve a goal. Even when it is true, it may make you seem whiny and unable to accept responsibility for your actions. Instead, address the weakness at the end of your statement, and explain how you have overcome it, learned from it, and are a better candidate now because of it.
The person you choose to look over your statement should be checking everything. Along with grammar and spelling errors they should check the tone of the paper, the flow of the paper, and the overall style of the paper. So, it makes sense that the person you choose to look over your admission essay should be well tuned in writing. Additionally, they should also be able to let you know if there is anything they feel you should omit or add. Once you have made the changes they recommend, then you should have them re_read your personal statement to ensure quality. If you want to be ultra_safe, then have yet another set of fresh eyeballs look over your revised personal statement.