The following is a look at existing use cases from the community and ‣ themselves. With Notion, many (if not all) of the use cases can be used at once or you can make them fit your system.
Reddit - NotionSo - Notion Setup & Workflow with GTD, PARA, Sprints, Checklist Manifesto, and more.
Projects, Goals, High-Level and Granular Tasks [use-case]
Sketch pad - Draw in Notion - NotionSo
Dashboards / Home Pages / Start Pages / ...