As I mentioned recently, I'm looking for a cover for my third novel. A number of artists are interested, which gets me thinking about what a cover should be.
From the standpoint of the author, the obvious answer is to show a scene from the book, preferably one that is dramatic and has something to with what is happening in the book—fits the theme, or the mood, or illustrates the setting, or ...
An alternative view is that the purpose of the cover is to get someone to look into the book—read the free sample if it's a kindle, read the back of the cover and perhaps the beginning if the book was picked up in a bookstore or library. So what you want is a cover that grabs the browser's attention, whether or not it has anything to do with what is in the book.
That isn't quite right, because the target is not a random browser but a browser who will like the book. What you want is a cover that will selectively appeal to the sort of person who likes the sort of book you have written. The obvious way is to signal genre—a spaceship for sf, a wizard and a unicorn for fantasy, a beautiful woman and a handsome man falling in love for romance. Not all fantasies, science fiction stories, or romances are the same, so ideally you target it more narrowly to signal the particular subcategory.
How does that apply to my current book? Its predecessor, Salamander, was largely about magic. Brothers is set in the same world with some of the same characters and magic plays a role in the plot, but no longer a central role. That probably eliminates at least one of the scenes I considered—a dramatic one containing four of the secondary characters, two of them engaged in a difficult, important, and striking piece of magical creation.
Another shows two of the central characters at the point when they swear brotherhood. That is central to plot and theme but not particularly dramatic. And since the two characters are both thirteen year old boys, it might signal that Brothers is a children's book—which it isn't, although I hope thirteen-year-olds as well as adults will enjoy it.
The one I have mostly been thinking of involves one of the two boys, is dramatic, is connected to events that are important in the early part of the plot but not central thereafter—and, since it shows one of the boys and his dog, again risks sending a false signal.
Perhaps I should not be thinking in terms of a scene at all. An alternative might be a cover mostly text with sketches of some central characters. Insofar as the book has a theme, it is personal bonds of trust preventing political fragmentation. Two pairs of brothers are central to the plot, one of teenagers and one of adults, a third adult pair is a little less central, all in different ways examples of that theme. Also a brother/sister pair. Would it work to have a cover that is mostly text, frame, and backgrounds, with a sketch of the two boys and, behind them, the two men? All eight?
Perhaps with, at the bottom, the sentence "Bare is brotherless back" to signal the connection to the title.
All of the sets of siblings are related. Another idea, probably a bad one, is to put a family tree on the cover with sketch portraits of the main characters, with the line linking each important pair of brothers emphasized.
Comments welcome, especially but not only from Brothers beta readers.