It is important to put yourself in the shoes of the Admissions Officer: why would your personal statement be unique, how are you different from the other candidates? Primarily you need to decide how you will divide your personal statement into digestible chucks. The most obvious way is to divide into paragraphs of 100 words. If you aim for between 500 and 600 words at most, it will help your admission officer when they have to read thousands of personal statements to find the perfect student.
Apart from this, interest in the subject can also be mentioned. To start with, one needs to explain the reasons for choosing the course. With this, they must also show that they have researched about the course and that they are keen to do it really. It may hold good if you tend to explain what you hope to achieve after the completion of the course. The good personal statements also include interests and hobbies of the candidates and, in particular, any responsibilities they had at school. Show the officers that you are good both for team work as well as individual efforts; show them that you are able to communicate well with others. You must not forget to tell them that you are not afraid of taking any responsibility on your shoulders. If you are smart enough, you may also add certain lines stating your expectations from the university.