Create headings in the document
When the documents are long, it is very impotent to make the user read them easily. one of the best way to do that is using Style.
In the Style there are predefined easy to use headings:
Write the heading and then select it, choose a style.
Make the document easy to read
In long documents it is best to add a table of content
Table of content always appears at the top of the document and will be generated automatically.
Have a look at the top of this document to see how the table of contents looks like