I'm looking for a book cover that would be competitive in the Science Fiction genre. The tone is grim but there's also dark humor throughout.
Most of the book takes place in the outer section of a cylindrical generation ship that is mainly croplands and walled towns. It is lit from above by lights on a distant ceiling that generate day and night, and "rain" falls during intervals to grow the crops. It looks vaguely like a post-apocalyptic Medieval Europe and curves gently upwards in two directions like an enormous multiple kilometer-wide half-pipe until reaching bulkheads. It's large enough that only one bulkhead can be seen at a time.
If you google "o'neill cylinder interior" that's kind of what I envision, except bulkheads cut the cylinder in half and there's a smaller gray cylinder "ceiling" inside the larger cylinder. Also, there are about 6 rivers in fairly straight lines from left to right, and after hundreds of years of travel and warfare everything looks a lot messier and more post-apocalyptic than those pictures. It's also not heavily populated and while cities are centered around Sci Fi metal facilities most people live in simple earth/wooden houses.
The spaceship spins to generate artificial gravity. Part of the book also takes place in typical gray metal Sci Fi corridors of the ship. They're accessed from elevators that are secluded in the bulkheads.
The main character is Marcus, a mercenary swordsman in his twenties who gets a pistol and bandolier of ammo midway through the story. He wears leather armor and has brown hair and eyes. All characters have distant North American ancestors and are fairly mixed/indeterminate in terms of ethnicity.
Other prominent characters include a jovial and somewhat fat pilgrim/maintenance technician in his fifties wearing a white robe over a jumpsuit, a standoffish female "witch" of about thirty wearing black as well as a deer cloak and headdress who has a sniper rifle with a wooden stock, and a 37ish cheerful but callous male mercenary captain in metal armor like a knight, who could be on horse or on foot.
I think that there are a couple options: make a standard roughly cylindrical generation ship; show the sloping half-pipe style mix of cropland, walled town, and forest; or show the main character and possibly other characters as well.
I would consider any cover that includes these elements. I like the idea of the main character Marcus with a sword and pistol in the foreground and curving nature/bulkhead in the background to show the mix of dark age/sci fi in this book. A large part of this book is the transition from ignorant swordsman to someone who understands the purpose of the ship, the journey, and technology and it would be great to see that transition conveyed.
However, I'm fine with anything that looks good, matches with the blurb, and will sell. I particularly want it to look great as a thumbnail since that's how most prospective readers will first see it.