You can repeat words or phrase or themes. In an article, sections are done in the same way to provide a framework so the reader can easily follow a thought. In this article, for instance, each section is put together in the same way, with the principle, followed by its definition, then it applied to graphic arts, and to writing. In a story, characters may have certain habits they repeat. A series of similar obstacles may have to be overcome.
Repetition is much used in genre fiction.
Readers of romances or mysteries have certain expectations for the stories, which writers flout at their peril. Contrast Take elements, which are not similar and make them very different. Contrast adds interest by attracting attention. Car Ads . In ads, color and typeface or weight creates contrast.