It's been said that one shouldn't judge a story by its cover. However, book purchasers are easily touched by a book's presentation.
As a serious author, you are naturally inclined to ensure your book is appealing to the customer as you possibly can.
When avid readers enter a store, whether it's online or a physical bookstore, they rummage through books or magazines of their interest, hoping to find one that suits them. You can also look for book layout via https://firewirecreative.com/.
Some cover art may scream to the customer, "Take me! You know you want to." And then there are the many that leave people sighing, wondering if they should risk buying a book with a plain cover.
So let's go to the basics. What can you do to ensure your cover art is a looker?
A book cover is supposed to tell an interesting story in a few seconds. Be objective when looking at a cover you created.
After grinning with the satisfaction that you accomplished making a book cover, take another look. Does the message you're trying to send out to a customer achieves its goal with the cover alone?
One thing that can help you a lot is by browsing online what kind of covers are selling like hot pancakes, especially the ones that fall under the genre you're writing.
Could you create a book cover similar to their design, but is unique to your story? I am not talking about copying other peoples' designs, but in allowing them to inspire your creative side.