I'm so in love with Vellum, I can't even begin to tell you how. It has saved me soooo much time and stress and produces beautifully formatted mobi and epub files with ease.
Simply click file and “reimport” your .docx file and it automatically breaks it up into chapters. You might have to manually type in the chapter and number but it's all there. Click book info to add the meta data, and Cover to add your cover.
The chapter elements can be dragged to different positions or if you're doing a boxed set, you can create volumes and drag each book's contents under it's volume name. Vellum has a great tutor built in to help you with your learning curve.
Click contents to choose your heading styles. I've chosen all caps for the first line, but you have options of fancy drop letters too.
Inserting images, weblinks, and changing alignments is super easy.
One of my favorite features is how easy it is to change front and back matter. Once I have dates and links, I can add and change the info easily. When that pre order is now a sale? Just swap out the wording.
There are other elements like About the Author that you can add with built in forms for social media.
Simply click preview to see what it looks like on a variety of readers.
When you're ready, click Generate and select the vendor/s you want to create a file for. In seconds you have a file that will upload beautifully. I've never had a problem with “meat grinders” using Vellum.
Yes, Vellum cost some money, but if you produce a lot of your own books and want control of the way it looks and the ability to change and update your file whenever you want, it's absolutely worth it.
https://vellum.pub/