1. Typos, spelling mistakes, and grammatical errors.
Nothing makes a bad impression quite like a typo or using "it's" when you mean "its." The importance of proofreading your essay cannot be stressed enough, and once you've gone over it several times, have someone else proofread it too. It can be hard to spot mistakes when you've nearly memorized the statement, so give it to someone with a great eye for grammar and spelling details. If you're unsure about rules, check out The Online Grammar Guide.
Also, before you send, make absolutely sure you're sending the right version to the right school, especially if you've mentioned the schools specifically in the statement. Believe it or not, Stanford Law really doesn't care why you want to go to Harvard Law or vice versa.
2. Writing about your failures/weaknesses without showing how you overcame them.
While personal and/or professional growth can be a great personal statement theme, you don't want to dwell on the negative too much. If you do choose to write about a failure or weakness, mention it briefly in one or two sentences, but then make the rest of the statement about how you conquered or overcame this particular obstacle.3. Regurgitating your resume.
Sometimes good personal statements come from talking about one of the experiences on your resume in more depth--especially when offering specific examples. What you want to avoid, though, is anything that reads like an annotated resume.
Besides probably offering up a rather boring read, you're also wasting a wonderful opportunity to show the admissions officers there's more to you than just a list of achievements; this is your chance to let your personality shine.
4. No hook.
Do you know how you feel after you've just read 50 pages or so of assigned reading? Well multiply that by many for law school admissions officers, and you'll see why your statement needs a hook: something to catch the attention of the reader and make her want to share a law school classroom with you because you're just that interesting.
And when should you get to the hook? There's nothing like the first paragraph of an essay to get the reader's attention and make her wanting more, so cut right to the action and grab her from the first few lines.
