A good photo or picture is worth a thousand words is a cliché but so true. When we write our books, covers are usually far from our minds except for titles. We writers are usually good at giving word descriptions of scenes and people, but I don't think we have the visual images artists possess.
A cover sets moods and gives the reader an idea of what will come without being specific. We hope the potential reader will open our books and flip pages. How hard is that? Very.
We do think about titles, sweat over titles, often do not like our titles, but we don't do this with the actual covers regarding colors and scenes and tone of book.
Unfortunately, most cover artists do not read our books so don't get a feel for them. They don't know our voice, our theme, our plot, our characters. Our covers end up "generic." I can't think of a better word and I know the artists can't read all our books. What are we to do? I don't have an answer. I hope, if you read this, you may have one.
Titles are important, maybe as important as the cover. In a series, I think using one word throughout the series helps. Tina Newcomb writes a series about a place called Eden Falls. All of her titles carry the word Eden. CK Albers who also writes series, uses the word Promise. I can't think of a better way to tell the reader the book is part of a series. Irene Bennett Brown in her Nickel Hill Series has great covers. I especially like Miss Royal's Mules with a young woman riding a mule. I write single titles and I try to use no more than two words and one if I can get away with it. For my next book, I know what I want to portray on the cover. So far, I haven't found a photo of what I have in mind for Footprints on the Wall. Note, the title has four words. I may need to change it.
When you read this, I would love to hear your ideas about covers and how you make a final decision. Covers do sell books.