Design for the thumbnail
Most people meet your cover at the size of a postage stamp, in a store grid or a phone feed. Before anything else, shrink your design to that size. If the title is unreadable or the image turns to mud, no amount of full-size beauty will rescue it. Big title, high contrast, one focal point.
Signal the genre
Readers decide what a book is from its cover conventions before they read a word. Look at the top twenty books in your category and write down what they share: the typefaces, the colour palettes, the kind of imagery, where the title sits. Your cover should belong on that shelf and then differ in one memorable way. A cover that ignores the conventions reads as a different genre, and the wrong readers click.
Type hierarchy
- Title largest, and readable at thumbnail size
- Author name second, larger still if readers know you
- Subtitle or series line smallest, and optional on the front
- Two typefaces at most: one for the title, one for everything else
Image
One strong image beats a collage. Stock photography works when it is chosen for mood rather than literal content; a lone figure, a landscape, a texture. Darken or lighten it where the text sits so the title stays readable. The stock library is grouped by genre for exactly this, and the Cover Creator's darken control handles the legibility.
Colour
Pick a palette of two or three colours and hold to it. High contrast between the title and its background; a single accent colour for the author name or a line. Then carry the same palette into the book page and the business card, so everything that represents the book looks like one thing.
The print details
The front cover you have just designed is one third of a paperback wrap. The back needs the blurb, a short author bio, and empty space for the barcode; the spine needs the title and author, sized to the page count. Work at 300 DPI with bleed on every outer edge and text inside the safe margin. The KDP cover size guide has the numbers, and the Cover Creator draws the guides.
Test it
Put the cover next to five real covers from your category at thumbnail size and ask someone who has not seen it which book is which genre, and which they would tap. Their first answer is the right one.