I was talking to someone recently about designing book covers. The easy part for me is getting the cover concept down. You launch these cover designs out there and once they are approved you tend to put them out of your mind for a while. The hard part is that they all come back months later for final production and if there are a lot at the same time it certainly keeps you on your toes. Often they have to be rephotographed and finessed in photoshop which is time consuming and then there is the layout of the full cover with all the elements put in place.
I always get asked how many covers I do a year. One day I will sit down and figure it our. It's a lot of work, for sure, and it becomes hard to plan your schedule because you never know which cover is going to come winging back for final production at any particular time. I have to say though that I do feel it is important to have many different creative projects on the the go. The creative faculty is like a muscle that you have to keep flexing.
I layed out this cover with a more restrained back cover and spine treatment but felt that it was lacking. I liked the idea of re-using the index cards for the back cover copy as well.