COVERS

It is the entrance, so definitely you have to improve the entry, otherwise, almost no one will be willing to go inside to explore.
Covers are the mirrors of the inside, magic mirrors that inform you of the subject, attract you to the content, and refer to make you adopt a positive attitude before you touch the printed material.
Covers need an artist to organize the components and elements.
If you well understand the priorities inside.
For me, to design a cover, I go through the contents and try to identify and weigh the inside as the editor does. Only then, I can design the cover.