Use styles, not looks
A converter cannot see that a line is a chapter title because it is bold and centred. It can see a Heading 1 style. Apply Heading 1 to every chapter title, Heading 2 to section titles inside chapters, and Heading 3 to subsections. The table of contents, the chapter files, and the navigation all follow from that.
Paragraphs and spacing
- One paragraph per paragraph. No blank lines between them; the ebook style handles spacing.
- No tab or space indents at the start of lines. First-line indents are a style setting in the ebook.
- No manual page breaks. Chapters start new pages automatically.
- Remove headers, footers, and page numbers. They have no meaning in reflowable text.
Scene breaks
Put three asterisks (***) or three hyphens (---) on a line by themselves between scenes. They become a proper scene-break mark in the ebook. A gap made of empty paragraphs disappears on conversion, and your scene change with it.
Lists, quotes, and images
- Make lists with Word's bullet and numbering buttons. Typed dashes and numbers are just text.
- Use the block-quote or an indented paragraph style for epigraphs and quotations.
- Insert images inline with the text, not floating in text boxes or tables. Keep them under a couple of megapixels; ebooks do not need print resolution.
Things to strip before you import
- Tracked changes and comments (accept all, delete all)
- Section breaks left over from a print layout
- Fields, footnote-style cross references, and embedded objects
- Decorative fonts used for body text; keep a plain serif and set the look in the ebook instead
If you write in Google Docs, the same rules apply, and you can paste straight into the EPUB Creator without exporting a file first.
Check the result
After import, the editor shows the manuscript beside the finished pages. Look at the chapter list, jump to a scene break, and open one image. Then run the fidelity check before you export.