Use Heading Styles to Organize the Google Docs Outline

Apply a heading style to create an outline entry

Google explains that the outline detects headings and lists them beside the document. Select the relevant text, open the style menu that normally shows Normal text, and choose a heading style. The heading is then added to the outline, where clicking it moves to that section. Subtitles do not appear in the outline, so use an appropriate heading level when a section needs a navigation entry.

Adjust navigation and inspect formatting separately

An entry can be removed from the outline without removing its document text. To restore it, select the heading and choose Add to document outline from the context menu. Google also provides rulers for alignment and a View menu option for showing non-printing characters. Those characters reveal paragraph, line, section, and page breaks as well as tabs and spaces, helping explain formatting that is otherwise difficult to diagnose.