Imagine you want to buy a book. You notice a book and you look at it more closely. But then you see that the cover picture is grainy. You turn to the first chapter and discover that the font is too small, and the text is unevenly formatted. Would you buy this book? probably not, that's why formatting is important. For customers, reading is a visual experience and therefore the appearance is important. So important that the customer will not buy a book if its appearance does not meet their expectations. The effort you make with formatting can prove to be a buying decision for readers. To help formatting a book that meets the expectations of potential readers,
A badly formatted eBook can quickly end in negative book reviews from readers, leading to lower sales in most cases. If you want to edit a text in Word and set it as an eBook, unfortunately, what you see in Word is not always what you see in Kindle Reader at the end. Therefore, I advise you to take advantage of experienced and skilled Amazon Kindle Conversion services, because they apply innovative formatting techniques that transform manuscripts into quality Kindle eBooks.
Below is just an overview of the best practices I recommend when formatting your eBook:

1. Remove Headers and Footers
The Kindle format does not support headers and footers in the eBook. If you have any in the document, they are simply neglected in the Kindle view, but at worst, it could lead to viewing problems in the Kindle Reader. So the simplest solution is to eliminate the header and footer. The same applies to the page numbering.

2. Insert an Automatic/Clickable Table of Contents
Readers and also Amazon prefer an automated table of contents, which contains the corresponding chapters of the book. Books in which tables of contents are less common are fiction. It should be included in each guidebook/non-fiction book. Readers like to navigate around the different chapters. This is simpler with an automatic/clickable table of contents.
If you insert the table of contents, remove the page numbers and possibly record only main chapters. For long texts with many subchapters, the table of contents can be long otherwise.

3. Use Styles
By default, Microsoft Word, Open Office, and other word processing systems allow you to use style sheets. This has the great advantage that every word, paragraph ... which is assigned to a style automatically inherits the defined formatting (size, paragraphs, frames, positioning etc.). This saves annoying, manual change, for example, of each individual heading.
For example, headline style 1 is used for chapter headings. This formatting recognizes Kindle and allows the reader to jump to these chapters. By using the styles for headlines, it is also easy to create the automatic table of contents.

4. Start Chapters on a New Page
You should insert a page break before each new chapter. This gives the eBook structure, and it is usually expected by the reader. The page break before a chapter can be defined in the style sheet via "Insert a page break before the chapter". This again shows that styles are really useful.

5. Check your eBook again before Publishing
Even though you have properly followed each of the steps regarding formatting, there are sometimes problems/mistakes with formatting or viewing in the Kindle Reader. Amazon KDP allows you to preview how your fully formatted eBook looks in the Kindle Reader. Alternatively, you can also view a copy of the eBook on one of your devices. Be sure to check your book before publishing. Do you think weird formatting that prevents the flow of reading, does the linking via the table of contents work correctly? Does the eBook navigation work with the tools in the Kindle Reader or the Kindle App?
If you find any errors, please adjust the original document and upload it again, then check again. You should repeat this step until everything is displayed correctly and no errors can be detected. Then you can publish your eBook on Amazon with a clear conscience and hope that it enjoys a large readership.

The Amazon Kindle Direct Publishing Platform gives you the ability to publish books yourself and sell them on Amazon. So you are no longer dependent on external publishing houses and can start right away.