Gather the Details
Start by developing a tag line for the book. As a one-sentence phrase of about eight to 10 words, a tag line sums up the book's theme, purpose or meaning. Make it eye catching and meaningful to your reader demographic. Use shock value, if appropriate. It can be either a question or a statement. For instance, "24 Hours to Live -- What Would You Do?" could create interest. Hook your readers with a tag line to draw them into the book.
Write a short synopsis of the book. As a short outline of the book, a synopsis lets readers know what it's all about. For novels, summarize what happens in the story without giving away the ending. For nonfiction books, let the prospective buyer know the takeaway for reading the book.
Gather positive reviews, testimonials and endorsements for your book. Three testimonials can help make a book advertisement productive. You need to build confidence in prospective readers by showing what others have to say about it. The deciding factor for many people when mulling over a book purchase is reading the positive reviews from other customers.
Transfer and save the image of your book's front cover in your image editing software.
Transfer to File
Position the elements in the advertisement. Once you have all of these elements, it is a simple matter of adding and positioning them on the page. Many graphic designers use QuarkXpress, Adobe Illustrator or Photoshop to design book or website advertisements.
Decide on a size for your advertisement. For posters, choose from 12-by-18 inches, 18-by-24 inches, or 24-by-36 inches. Add 1/2 inch to both the length and the width to allow for a 1/4-inch bleed on each edge. For example, a 12-by-18 inch poster should be 12 1/2 by 18 1/2 inches. An advertisement on a bookmark usually runs about 8 1/2 long by 2 3/4 inches wide.
Add a background color to the advertisement that complements the colors in your book cover. Place your book cover image somewhere on the poster, usually near the top. Add your tag line in large letters.
Type in the book title underneath the tag line in larger letters. Add your reviews underneath the book title or in open areas around the entire ad. Finally, place your synopsis at the bottom of your ad in smaller letters. Once you've captured readers' interest with your tag line and book cover, they will most likely come in closer to read more.