Whether authors want to admit it or not, readers do judge a book by its cover. It is the first interaction they have with your book as they walk the aisles of the book store or browse through an online store like Amazon. They'll wander past and pick up the the books that catch their eye. Once they pull a book off the shelf they'll read the summary on the back and sometimes take a peek at the first chapter. If all of these things intrigue them then they'll purchase the book. If any of these elements are off they may put the book back.
You must remember that your book is an entire package. All of its elements must appeal to readers. If they don't like something they may move on.
A cover design must be eye-catching to attract a reader's attention. Your blurb must clearly convey what the book is about without giving away too much, it needs to be enough to catch their interest and make them want to find out what happens. You can't skimp on any of the details. You put in all the work writing the book but you must also put the effort into the 'packaging' to make it appealing to readers.
We have all taken that stroll down the book aisle and picked up a book simply because you liked the cover. Then found yourself putting it back because the summary was confusing or didn't make the book sound intriguing enough to make you want to read more, or maybe you read the first page and it didn't grab you. If any of the book's elements are lacking then readers may bypass it for another. It may not be fair to your book but if it isn't attractive to readers they won't give it a chance. You writing may be phenomenal but if a reader can't get past the cover they'll never know it.
When readers saw the original cover of the first book in my Chosen series they ran the other direction. The cover was too dark, it was a hand drawn cover that wasn't that great, and the font choice was awful. My summary on the back was also way too long.
Graphic design isn't simple and it takes a lot of practice to get things right (I've been doing it since 2012 and there is a lot I still don't know). A designer must learn how to place and space images to make the final design pleasing to the eye. It isn't about slapping the first image you see on there and calling it a day. There is an art to creating a final design. There are things you must do to create a cover for a print book. You need to acquire a template from your printer/publisher and your images need to carry the appropriate licensing so you can use them. Most designers purchase images from stock sites. Your images must be appropriately sized so they cover the book from front to back. It needs to be a smooth transition from front to back as well. If there are jarring inconsistencies and it appears as if you tried to force the images to appear to be one image it will be awkward and off-putting.
Just because you can do something it doesn't always mean you should do it. Don't do a drawn cover simply because your best friend's, cousin's, aunt's dog can draw, and they're going to do it for free. There is a difference between a professional cover artist and someone who creates what most designers refer to as refrigerator art (which I found out).
Before you decide on the final look of your design, go and take a stroll down the aisles of the bookstore and look for the genre of your book to see what other authors have going on as far as designs go. You're going to want to make certain your cover reflects your genre, you wouldn't have pretty pastels on a horror cover. Look for current trends for your genre as well. When my Chosen series originally came out the trend in YA covers was to have a glossy finish on the cover, it has since shifted to having a matte finish. Are object based covers currently in or do you see more model based covers? Make certain your design fits the book, don't throw stuff on there simply because you believe that it's the "in" thing to do. Your cover is as important to your book as the content inside. It isn't a throwaway and you shouldn't dismiss it as unimportant. If you're self-publishing you will have more control over how your cover looks than if you go through a publishing house. If you go through a publisher you may have little to no say in the look of your cover.
When creating your book you need to think of it as an entire package. As with any product, the packaging is important to attract your customers. You are the one who will lose out if readers pass up on your book. Take a look at your book from ever angle and take pride in the overall finished product. Make it the best that it can be so your readers will be as excited about it as you are.
This image below shows the original cover of the first book of my Chosen series and the current cover. The new cover is much more appealing to readers. I loved the original cover when I originally had it done but soon realized it did not make a good cover image. I made a lot of mistakes when I first published because I knew nothing about the industry. I hope this blog with assist those who are starting out so they can avoid those same mistakes.
Take your time and do your research before you settle on a cover design. Pick a good designer, ask other authors who they use, check out cover groups on social media, and find a designer who's a good fit for you and your book.