Select a graphic. A picture provides instant recognition for the potential reader and helps set the mood of the story. You may use your own photos or one that you find on the Internet, but be careful. If you use any image you find on the web for commercial purposes, make sure you have permission to use it. Royalty-free photography websites allow you to pay for photos without having to pay a royalty per sale to the photographer.
Create a template on your photo-editing software in a rectangle, in even dimensions, that resembles the shape of a book. You can make this quite large to give you room to create. Make the rectangle 1600 pixels wide and 2400 pixels long. Use bold colors that draw the reader's eye toward the cover. Remember that colors inspire certain feelings within the reader - blue for confidence, orange for appetite, red for action and green for prosperity.
Add layers to create depth and a professional touch. Blocks in different colors for the title or author name add a three-dimensional look to the cover. These layers can include your graphics, should you not use the graphic as a full background. If you are using a photo-editing software like Photoshop CS2 or newer, Smart Objects allows you to manipulate three-dimensional layers without affecting the original image.
Get creative, but be concise. You can play around with the font of your text but make sure it is large and clear enough to be legible once you reduce the book cover to thumbnail size. Bright, colorful boxes make text pop when placed upon them, and you may choose clip art to include shapes to the overall design.
Add a tag line in addition to your title and author information. This is a brief sentence that captures the reader's attention with a tantalizing hook for your story. It can be in smaller text than the rest of your information, but make sure it is large enough to read no matter what size the cover happens to be.
Once you are satisfied with the final product, save it as another file and crop to the thumbnail version. The size of these dimensions will depend on the publisher for the e-book, so defer to their specifications. This will give you the opportunity to see if the graphics and text are still legible in the smaller size, so you can make any necessary revisions.