I have written my PS, but I don't know how to begin. Is there an established form, like 'Dear Sir/Madam' or do I just send in my statement, partitioned into paragraphs, and that's it? Should I write my name, address and contact information in one corner, universities info in another or are these things redundant since my PS comes in a bundle with a bunch of other documents that have my name all over them? How do I end, 'Sincerely yours, Robotron' or nothing?

Thank you.