I use Google Drawings to create all of my Kindle eBook covers.
Yes, just Google Drawings.
I set the drawing dimensions to 1600 x 2560 as per Amazon’s guidelines. Follow these dimensions to ensure you do not have a blurry cover.
Typically I’ll choose a solid color background, but you can do images, shapes, anything that comes to mind. I like a simple approach to maximize interest among the noise that most covers have.
When you’re done adding your book title, author name, and any other text, you can export as a JPEG, which is what Amazon needs for cover uploading.
There you have it, a brilliant book cover made easy.