Back in 2012, I published a small e-book on Amazon, partly because I had something to say, but partly because I wanted to see how easy/difficult it was. The Little Guide to Teaching Yoga in a Gym served the purpose and sold reasonably well, too, so it was a useful exercise.
At time time, because I didn't know any better, I designed - and I use the word loosely - the cover myself, thus:
Now, I've revised and updated the content and republished it, again as an e-book, but this time I've used the services of Shar at www.fiverr.com. She also did the cover for Nine Lives and she is really quick and great to work with. I'm sure you'll agree that what she has produced is much better than my humble effort:
So that's it: I'm not a cover designer, but fortunately I know someone who is, and it's worth paying for a job well done.
The Little Guide to Teaching Yoga in a Gym is available from Amazon for just 99p.