I'll just add a bit to the editor cover conversation. First of all, yes this is something you talk about with your editor, not your agent as your agent can support you in your endeavors but has no control over what the publisher will decide as far as covers go.
But I am quite obsessed with covers, and have a decent eye for cover design, and so I do like to have my two cents. That being said, I understand fully that at the end of the day the publisher gets the final say.
So with the above said. . . two stories:
The first is when my American publisher was going to put out the paperback of my book. They were going to change the cover and sent me what they planned on using. I really didn't like it. So instead of freaking out, I sent back an email detailing precisely why I didn't think it would work, and suggestions that could do something similar but not the same. It was professional and polite. They were very receptive and took my suggestions.
Second story.
I discovered an artist online that totally captured the spirit of what I thought my book was trying to as well. I sent a link to the artist's page to my editor. I didn't say I wanted him for my cover - because usually in YA books you get a photographic cover anyway - I just said that I thought he was amazing, that a particular work of his was just perfect for what I was trying to convey, and that was all. It was more so that she and I were on the same page as far as packaging the book. Less of a hard and fast suggestion. It was just a really cool thing I thought she'd like.
A couple months later I learn that she is actually pitching that artist to do the cover. And then marketing agreed to it. This is Penguin, btw, which is a pretty big house - I point this out because a lot of people say that you can't have any kind of influence unless it's a small publisher and that's not quite accurate.
My point, well, I knew that at the end of the day my publisher had the last word - and they still do. I've seen a sketch of the cover and offered some suggestions. They took some, but not all. And that's fine. But I don't think authors should be scared to share ideas with their editor. They just can't expect anything to come from sharing their ideas. Also the more general the better. So instead of saying, "I want a purple unicorn with a rainbow of black yellow and red behind him, and I want this font and my name to be on a slant and and . . ." find artwork that you think captures some kind of essence of what you're trying for with a cover. Comparable covers as well. Specifics can make people feel boxed in, but a general feeling, mood, tone, quality of art - poster art vs painting vs photograph - well that allows for the imagination to flourish.
So yeah. Them's my thoughts on the subject
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