So here's a cover I made.
Yup one of those covers I showed you earlier.
And these are all the layers I worked with.
The last picture was the background on which I blended the picture of red leaves so it looked something like this:
Then I cut out the background from main image and placed it on top of above image.
Later I uploaded the final image on Canva, applied the text, adjusted the brightness, saturation and contrast to my liking, added other elements like the golden bar you see at the bottom and finally the cover is done.
You can do the blending and cutting out steps which I mentioned earlier by using the app Adobe Photoshop Mix easily available on Google Play Store for free.
The rest of the adjustments were made on Canva.
If there is any other cover in this book that you would want to know the steps of, mention in the comments.