The PS should always end on a positive note, and the conclusion should summarize the body of the statement. It is important to reiterate the primary message of the personal statement and thank the audience for their consideration. This will leave the reader with positive images of the applicant as they put the personal statement down.
Being an Apologist _ You do not use your personal statement to explain why you lack certain skills or experience. The point of writing this short paragraph is to sell yourself and this involves highlighting your strengths instead of apologizing for your weaknesses which in itself is a sign of weakness. The time and place for discussing flaws in your suitability is the interview and at that point, you must focus on how you plan to overcome any holes in experience/skills etc.