here is my design for marketing book. there i Blue family as main color. I used Smiple-Modern concept which look clean and eye-catching.
The main image is standing out blocks illustration with cute details.
the Big tittle going on the bottom and stand out as center point,
there is the fonts :
- Tittle: Bold Cambria Font
-Subtittle: Colus Font
-Author: Dream Attack Grotesk Font
* All font is free font
Im sure this will be look good at bookstore..

the back side is complete, you can find the blurbs, testimony, author details, publishers, and price. The spine also come with title and author.

big thanks, enjoy!