Your recommenders are not required to use any specifically designated forms when they write your reference letters. The letters may take any format which may suit your recommenders. Be very careful when you choose who you ask to write your letters of recommendation. These letters will be used by the committee to access your previous experience, skills and future potentials, which means that your recommender should have adequate knowledge of you as a person and of your abilities to work and learn. Since you are required to submit two letters of reference is a good idea to ask people who can evaluate you from a different perspective to write you a reference.
The ideal recommender to write your first letter of reference would be your supervising professor or a member of faculty who knew you well when you were studying for your undergraduate degree or equivalent. For your second letter you could ask someone who knows you within a context involving your working life, volunteer activities, community or other extracurricular activities. For both letters the ideal recommender would be somebody who taught, supervised, or worked with you in a senior or managerial position.
The most helpful letters of reference are those which give information about you as an individual, your personality, previous experiences and achievements, and an evaluation of your potentials.
Recommenders must explain their relationship to you, the number of years of their acquaintance with you, and give their current position and physical addresses, email addresses and contact numbers which the selection committee can use to contact them if necessary.