(This was probably pretty close to 'state of the art' back then.)
Today, we can make covers that show anything and everything, from dinosaurs and aliens, to spaceships and machines which conform to no known laws of physics, and in this age of self-publishing, you can certainly judge a book by its cover; using it as an example of how much effort the author has put into his or her work.
One of the biggest complaints I've seen about authors who have their books published through a major publisher, is the lack of any control over the cover of their book. Sure, it sounds great, getting specific artists, marketing majors and designers all working on the first thing people will see when they pick your work up, but (since we're using old sayings today) too many cooks spoils the soup. This can end up with book covers that are the literary equivalent of a 'hot mess'. Where the idea of the book is lost in efforts to grab the reader's eye and draw them in with little regard for whether or not they would be willing to read the type of story which is inside.
(Um. Okay. Yeah, this says Horror story.)
Self-published authors need to be careful, though. A lot of photographers actually copyright their photos so that you can't just snag any picture you want off the internet and slap your title and name across it. As well, a lot of people now are getting used to the signs of photoshopped images, even if they might not realize it. Ask anyone these days and I'm sure they can tell you they've seen pictures which just "didn't look right" even if they have no idea why.
Artwork aside, there are a lot of considerations for a perspective self-published author. The proper Title is another issue, as well as font, size and placement of the Title.The third major detail is, of course, the author's name.
Some established authors, such as Mr. King, seen above, are so well-known, that their name actually takes precedence on the book over the title. Some are so well known, along with what they write, that they can forgo both the title and the artwork and just put their name on the cover and call it done.
(Pretty sure she could get by without titles at all, at this point. We all know what's behind this cover just based on who wrote it.)
Most of us self-published authors, aren't that well known yet. So while our name is important to have on the book, it's a distant third to the artwork and the cover.
So, let's start with the artwork, as that will usually be the first thing to grab a potential customer's eye.
Cover art thoughts.
1. It should be attention grabbing. This isn't as obvious as it seems. Sure action scenes and half-naked people will get attention, but also symbols and items can be used. It's not just images that make you stop and go "WOAH!". It's things which make you do a double-take and think "What is that?". There's a current trend towards simple and plain designs currently as well, a silver sword on a black background, a raven's black head against white, a crown among flames. Part of the reason for this trend is that with the advent of ebooks, advertising is based more on word-of-mouth than books which are trying to snag your eyes from the shelf at a bookstore, and it's becoming a way to cut costs. The power of a cover to attract attention still shouldn't be underestimated by any means, though.
2. The genre of the book should be obvious. People have expectations, and when those expectations aren't met, they tend to get cranky. It really goes without saying that a sci-fi/horror novel shouldn't focus on a beautiful woman and her handsome, shirtless beau riding a horse into the sunset on a beach, and if it does, the title and the blurb on the back or the description page better do a damn good job of telling the reader that they're not about to start an erotic romance story. Likewise, I wouldn't expect to see a dragon on the cover of a crime noir book, nor a headless corpse on the cover of a romance novel. Imagination being what it is, there can be exceptions, but if you're going to start a fight, why would you choose to start at the bottom and battle your way uphill?
3. It shouldn't be too busy. You don't need to cram every character's face onto the cover, nor do you need a three-way split for the three main turning points in the story. Space is limited (unless you're doing an art book, which is a whole different can of corn) and you need to remember to leave room for the title and your name. It can be tempting to want everything on there and think "Well, this might grab some people, but not others. The other's might like this though, so we'll throw it in there too. And let's not forget this for the younger/older audience...". Throwing everything at the wall and seeing what sticks is not an effective way to do a book cover.
The other main component of a cover is the Title. I'm going to try not wading out too deeply with this right now, save for how it applies to the cover.
When you're coming up with your title, take into account that it's going on the cover of a book. Titles need to be read from a little distance, and in small thumbnail forms. This means longer titles become problems very quickly, as they either get smashed together as to become illegible, or they cover up the artwork you just spent so much time (and/or money) on. Generally speaking, the fewer words you can use, the better, as the bigger and easier to read you can make them without causing collateral damage to the artwork or the eye.
There isn't really anyplace in particular you're required to place the Title and the author's name. The top, the bottom, down the side. Wherever it goes though, it should be legible, the art shouldn't be obscured too much, and the reader shouldn't have to hunt and peck for any of it.
As usual, these are my opinions, based on my own observations and any writer should feel free to disregard any part or the post as a whole. Feel free to leave a comment at the bottom calling me a loon. At the very least though, it is food for thought. Cheers.