Three Things Consistently Wrong With Self-Published Books

Well, what a brave new world this is. The authors have wrestled back control of the means of production, publishing companies are taking a massive hit, and almost anything goes. Just take a second to look at AuthorEarnings and their reports. I think the self-published royalties are enough to speak for themselves. 

It's been said a thousand times before, but there really never has been a better time to be a writer. If you really want to go it alone - no editor, no cover artist - you could feasibly put up a book on Amazon for literally zilch, no expense incurred, and if it's good enough, make a reasonable amount from the sales. 
But there's a hitch. 
I read a lot of self-published work. As someone who writes it myself, I feel a sort of moral responsibility to keep the community alive in my own small way. There's some great stuff out there, easily rivalling, or bettering, a lot of the published material on the primary shelves of international book stores.  But let's be honest. There's also a lot of rubbish. 
The gatekeepers are stepping back. That much is obvious. But with that process comes a penalty. Now anybody can get their work out there. I don't doubt that everyone is a potentially decent writer, but there are some consistent mistakes getting in the way. And I don't even mean the writing itself. So, here's a cursory list of some of the immediate turn-offs I come across in my day-to-day stroll through the digital bookshelves of Amazon. 

1. Terrible Cover Art 

The usual caricature of an author is one of a destitute alcoholic, prying open the next tin of dog food because it was cheaper than baked beans. Fair enough, lots of authors are broke. But that is literally no excuse for bad cover art. It's superficial to say, but it's true: the front cover of a book is the first contact a reader will usually have with your work, and the first chance they'll have to evaluate your professionalism. If it's pixelated, or ugly, this reflects extremely badly on however great that novel of yours is. 
There isn't much excuse for this in 2015. With the self-publishing industry booming, plenty of sites have risen up to take care of this, and inexpensively. Myself, I use James at Goonwrite. I haven't found a better cover artist to date, and his prices are insanely reasonable. (I should say that I'm not in any way affiliated with James or his work, I just admire his designs.) 
If you really want to go it alone, a few hours on photoshop could land you something equally as professional looking as any cover artist could do, if you have the skills and eye for it. Don't slack on the cover. It's the first thing the reader sees. 

2. Terrible Proofing/Editing 

I'm in the worst possible position to be lecturing about this. A year or so ago I finished my first book, How to Build a God, and excitedly sent it off to a formatter I found in about 2 minutes on Google. I was just blown away that I'd finished a book at all, to be honest. I couldn't wait to get it up online. Sure enough, when the formatted copy came back, I threw it up on Amazon, and waited. A few people liked it. Others were quite vocal about the sloppy editing however, as well as the occasional typo. And I don't blame them. If I notice a typo in a book, I put it down. The author obviously hasn't put much care and attention into its presentation. If they didn't believe in their work, why should I?
I took the book down and learned my lesson. These days, after the final draft is done, I go through my books with a comb, reading it 30 to 40 times. Yes, it's tedious. Yes, you begin to doubt yourself. Yes, you want to take an overdose of barbiturates. But the sense of satisfaction at the end is second to none. You know that it's as error-free as it can possibly be, that you don't need to lie awake at night worrying about some effect/affect mixup that'll completely undermine the book you spent years writing. 
Equally well, for the financially more secure of you out there, editors are all over the net, and willing to take your manuscript for a reasonable price. I've tried it a few times and for the most part they're wonderful. They have a vested interest in making your work as good as it possibly can be, and if they're up to the job - as they almost always are - they'll do just that. There's nothing worse than finding a typo of plot inconsistency in your own work months later after hundreds/thousands of people have bought it. You can edit the book, but you can't edit a reader's memory. 

3. Terrible Writing 

Ah, this is rather a difficult one - isn't it? The whole game is completely subjective, who am I to say what's terrible writing, and what isn't? I wouldn't claim that power; I hope no one would. But there is such a thing as sloppy writing, certainly. And the sloppiest habit I know is: egotistical writing. I'm guilty of this one myself, probably. When I look back through the trash I used to write in my teens, all I can see beneath the words is, Look at me! I'm so original and unique! A number of books - memoirs, I've found - are designed with promotion of the author in mind, and only the promotion of the author. The reader can pick this up in a second. Constant preoccupation with trying to communicate how talented the author is, or how many words he/she knows, or how many strange literary techniques he/she has picked up, does little to draw a reader in. 
When you really think about it, writing is human programming. You input information with a desired effect. Hopefully the output is what you wanted. Those diodes lighting up in your mind as you write your masterpiece, you hope they'll light up in the reader's mind too when they actually come to read it. It's a form of coding. Books have been around a long while now. Readers are pretty clued up to cheap tricks. They'll smell it a mile off.
Ahhh, you say, but what about the Fifty Shades of Grey of the world? What about the Twilights, etc. Well, they served a purpose. That much is obvious. Millions of people found something they needed in those books and bought them. They weren't necessarily well written, but the code did what the code was supposed to. They found their niche and they filled it well. 
Equally well, all books have a niche, yours included. With enough time, and with an adequate foundation, (a good cover, good editing, and good writing) you're bound to find yours too. The three items above have just been foundations, nothing more. They're the pillars your novel stands on. They won't save a terrible book, but they could certainly ruin a good one. Get them right, and the rest follows automatically.