What is a book? Front Cover

I started to do some simple sketches to determine a feel of the types of designs that will be included on the first page of my book. I will use limited colours such us black, blue and white related to the theme. The illustrations would be simple yet powerful, suiting the theme.

As I really like the first idea I have draw it with the fine linear. The illustration represent moons which suit well my chosen theme.

I have done couple of digital versions of the sketch which I think are very successful. I will use the white illustration on black background for my front cover as I want my book to be black symbolising the night. 

 For the back of the book I have come up with some ideas of illustrations. For the back cover I will put a short description of the book and a quote. I have done couple of sketches and digital versions of it. 

Digital version: