That is a very big question. There are many things that would come up, and it is difficult to list them all off here. In order to determine what guidelines to use, in any situation, keep in mind the purpose of your document.
If your purpose is business focused you will assume that getting your point across clearly, and concisely will be of utmost importance. You don't need flowery descriptive language. Use as few words as possible and be sure that all the information needed is included. Usually, the purpose of a business document is to put across some specific information in a short paper. Of course, there are many types of business documents so this is not a question that is simply answered.
In an academic document, you must be very thorough and incredibly detailed. You must use complete references for every fact you list. You are usually not presenting one simple concept, but rather, a thorough account of a subject which covers everything about that subject.
Hence, an academic paper about teaching English will begin with an outline, then progress through an explanation of the steps that are necessary and how to accomplish each step. It will contain quotes from experts and use examples of ideas and styles.
A business document presenting an ESL class will tell us the necessary facts, such as time, place, who is teaching, and how long each class will be. It may give a list of the topics that will be covered, but will not go into any detail of why they are covered in that particular order.
Does that answer your question?