When I design my book covers I will try a few different versions using photographs or creating images for the back ground image. Being able to make your own covers as an indie author can save much needed money on paying an artist to create one.
Now most people have a camera, even if it's on your phone so snapping an image is easy to do. There are also plenty of free photograph editing tools to use. For this book cover I used a photograph from my local graveyard and one from a ruined monastery and just some basic alterations.
The next step is choosing your font for the text, this in this cover was more important than the background image.
The font on the left put more emphasis on the author name and unless you're a Steven King level author it's a waste of time, the story and title are more important until your name is known. The font is also a very rigid style and not in keeping with the light hearted comedy of the story. The wording just didn't stand out enough and the books title was lost.
So in the second cover I went for a more fun style font and the title of the book took centre stage. While the author name is still there to be seen it doesn't overpower any more than the sub title of the series of books.
When you have spent months or years creating your story then you want to get your cover right and nobody knows the look of the cover you want better than you. Spend some time playing with getting your cover right to how you want it. Don't go with something that you don't really think lives up to your story, if you wrote a story then you have to be creative so playing around with a photograph and a bit of text is easy.
A cover is important so have a go and just play around to make the cover you really want to be the first thing a potential reader sees.