There are bad covers out there; we have all seen them. The ones with the glaring, eye-searing colors, painful design, and horrid photoshopping that should be a crime against humanity. I could go on for days about the horrors I have seen lurking in the dark corners of bookshops, but I’m sure you’d all rather I talk about what makes a good cover. The kind that stands out on a crowded shelf and demands you buy it.