10. Use poor spelling or poor grammar _ This one should be pretty obvious. Academics on admissions committees are generally high achievers with high standards who won't disregard even simple typos. If your personal statement is not technically perfect, it can make you seem sloppy, lazy, or inattentive, which are not qualities anyone wants in a future colleague. Remember that the people skimming your essay are seeking a reason to reject your application and make the pile of possible admits smaller. Always get someone with strong writing skills to review your essay.
5 _ Get help writing your personal statement _ No this doesn't mean get someone to write it for you! But getting help writing your statement can be very useful. Others can point out spelling mistakes you may not have seen, or point out how skills you have could be relevant. The very minimum you should do is get a friend / parent / tutor to look over it before you send it off. It could be the difference between acceptance and rejection.