For The Distance Between Stars project I used Photoshop to create an image montage for the cover that matched what the author was envisioning. I also used Illustrator to create a map that depicts the fictional country in Africa where the story takes place.
A mockup of the book cover.
While the cover looks like a simple photograph, it's actually three images edited together with some fancy Photoshopping. For the record, I had to set the type in Photoshop per the publisher's instructions. I personally would have used InDesign for typesetting.
The three stock photos used to create the cover image.
The original hand drawn map that the author provided is on the left, with the first proof of the digital map on the right. I used Adobe Illustrator and the pen tool to create most of the map.
The marked up proof with revisions is on the left, with the final, approved map on the right.
The map in my signed copy of the book.
Even after all these years it's still cool to see my name in print.