3. Add the chapter heading as Heading 1 Style
4. Format the book content as “Normal”
5. Use Paragraph Justify for book content so that it fills properly.
6. Select Your book Title and Subtitle and Author Name as Title Styles
7. Add page break at the end of each chapter, Use Ctrl + Break or Goto Insert->Page Break
8. Use show hide formatting to see page breaks.
9. Keep the font size as 12 for the book content, Heading title will already have its own sizes, this looks good in kindle.