A great exercise to conduct before you begin to put together your admission essay is to start with a sample. This way you can see exactly what goes on a personal statement and you can also check out how the tone of the writer is and what they actually are emphasizing.
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.