A working thesis and rough outline can help writers get started.
The American Psychological Association encourages the use of headings to help readers follow the organization of a paper. For an original research report, the major headings often follow a standard model: Method, Results, Discussion. The introduction does not have a heading; it consists of the material between the title of the paper and the first heading.
For a literature review, headings will vary. In Luisa Mirano’s paper about treatments for childhood obesity, she used four questions to focus her research; the questions then became headings in her paper (see APA-5b).