I haven't posted much from a combination Jewish internet-less holidays/illness, but that'll be over in a week (the holiday part and hopefully the other part). Please know that if you post a comment past 6:15 pm EST tonight, it might not be approved until Saturday night.
Every once in a while, we get someone who's made their own cover. Either they've self-published already and are sending a copy or a copy of the cover, or they just designed a cover for what they hope will be their published novel. Let me say this: We love it. Why? Because they're so hilariously bad that we get a chuckle before moving on to the query, which is the only thing that concerns us anyway.
No, you do not get to design your own cover. I remember long before I worked in publishing and was submitting manuscripts (none of which were accepted), and I had wild dreams of designing my own cover. I even went into Photoshop, but at the time I wasn't very good at it and didn't come up with anything. I thought I could do a better job than those awful people who make covers using stock images (i.e. public domain) and something to make the author's name look shiny. Well, I was wrong. Unless the author has a master's in artistic design, with a speciality in commercial design for the book market, the cover will suck. So hard.
Oh man do I love them. There's the memoir covers made using a personal picture with the title written over it using Microsoft Paint. There's the self-drawn fantasy covers with the woman with impossibly large breasts standing beside the hero. There's the person who thinks a photograph of an empty building would look nice as long as they went a little nuts with the bevel/emboss function of Photoshop. And, last but not least, the person who pasted some photographs and newspaper clippings and drawings to a piece of paper and did a color photocopy, so it looks like some kind of collage.
Yes, you can not like professionally-done book covers. Many authors and readers don't. But you probably couldn't do better.