For some books, I may use images for the chapter openers, and also for break - in - thought icons, etc. (Basically, I try to get the ePub to look as close to the printed book as possible). (epubsecrets.com)
Naturally, if your book has part and chapter openers, you'll insert those where needed. (bookdesignmadesimple.com)
Interior design is subtle, but necessary, including things such as the table of contents, chapter openers, page breaks, running heads, and page numbers. (ingramspark.com)