After you have written down the date, you can move on to the body paragraph that contains your intention to apply for job. Things you would state include your objective of joining the company? How can you enhance company's productivity? What is your previous experience in the field you are applying for? What is your academic background and how it can help you in your job? Lastly you can list down basic skills and experiences that you have attained from previous jobs, if any.
"My advice [to parties contemplating having an LOI] is to proceed with caution before signing any such document. As a general rule (and there are exceptions), I urge the parties to go right to the final documents and "dot all of the I's and cross all of the T's," rather than go through this interim step of a letter of intent, which has many potential traps."