I have been teaching my students how to add headings to all of their essays over the past five years because I think most of their writing for their careers will be in online environments. As anyone who does a Google search knows, being able to scan the headings of an article is very helpful so that you can figure out whether that article answers the question you are asking. Additionally, scanning headings (if they are written correctly) allows you to understand the main point of the article quickly and also to find the part you are most interested in reading. You can make headings by making a short version of your topic sentence in each paragraph. Generally, the shorter, the better. What I have found is that when my students use headings in their papers, it helps them to actually organize and write their information more clearly because making the headings helps them to realize their main points. If you've done a good job on your headings, a person should be able to read the title of your paper and all the headings and have a good grasp on what your article is about.