How To Write A Professional Letter Layout . How much to the right hand side is up to your personal preference. First and foremost, you should write your name and address at the top of the letter, either on the left side or center of the page. FREE 7+ Sample Business Letter Templates in PDF MS Word from www.sampletemplates.com Include addresses and the date. In the following paragraphs, provide more information and details about your request. When writing a professional letter, you should include your full address in the top left or right corner.