Unlike a typical UK official letter format, the US has a couple of variations, the full block format and modified block format. The former simply means all elements of the letter, from the return address at the top down to the writer's name at the foot, are justified left. the latter, on the other hand, incorporates some elements to the right or centre, rather like the UK official letter format.
Use bullet points to segment the content. Since we are working on a 3 paragraph maximum length for your letter, the content can be further broken down by bullet points. Similar to this article, where I used a numbering system from 1 to 6, it allows the reader to glance down and get the outline of what you are trying to say. At the beginning of your paragraphs, use bold face font. This is a trick that many marketers are familiar with. If you highlight the first few words of each paragraph with compelling text, the reader will want to read more. And this is a good thing! Give your printed letter the eye test. Since most people end up writing their letters on a computer, and sending them in digitally, it might be a good idea to actually print it out, look at the font size as well as the content and see how easy it is to read. Since the company will be actually printing out the document and reading it by hand, it makes sense for you to do the same. These are just a few great tips that you want to remember for your cover letter format.