Unless the identity or mannerisms of a character are hidden for dramatic effect, one thing to avoid when creating fictional people and worlds in to make sure they actually do something. Who am I referencing when I say "they"? Well, anything--everything! Anything relevant, that is.
In other words, one of the greatest perils of fiction writing is making certain one's characters are not merely floating, talking heads/mouths with no surrounding environment or appropriate gesticulations. Even if your character is standing completely still the reader has no way of knowing this unless informed--by the author. A wave of the hand, the twitch of an eyebrow are all methods of implying a character's mood. Utilizing descriptions like these can rid a story of child-like explanations of emotions, e.g. I am sad./Billy was happy.
Character Diversity
Another characteristic of bad fiction writing is a lack of diversity of characters. If each character understands one another without incident or speaks using the same voice (without dissenting opinion) then it is almost certain to be a bad story. However, this can only be true unless a lack of character diversity is being used as a plot/comedic/dramatic device. As you can imagine, I would only suggest a very experienced writer use such a technique. An example? Animal Farm, by George Orwell.
Furthermore, a variety of characters who all say the same thing is indicative of a pompous author. And if there's one thing editors cannot stand, is authors who attempt to pound concepts in the head of the reader. For the sake of ibuprofen, please keep off of the soapbox.
Ebb & Flow
When constructing the story itself (outside of characterization and plausibility), a bad fiction writer tends to jump from one scene to the next without transitions. Plot devices withstanding, of course. Mainstream literary fiction craves conceivable transitions. As I'm sure you know, the vast majority of both print and web-based literary magazines want to do without genre fiction. (Don't ask me, I adore genre fiction.) In any case, for the love of realism, a good fiction writer must adequately explain why and how a character goes to a certain place, reacts a certain way, or smells the way she does.
If you haven't already guessed, character diversity and plausibility (here called ebb & flow) are interconnected. Why? Because something one character may regard as completely reasonable, it is advised that another character (for adequate reasons) find this same situation/item completely insane. And as a human endowed with the power of empathy this goal as a good fiction writer, is completely within your grasp.
The Ending (Deus ex Machina)
Generally, I am of the opinion that stories do not end: The bad guy is never entirely overcome and the protagonist may not live--let alone live "happily ever after." It seems this sentiment goes against many centuries of American literature. (Those of you outside of the States can rest assured.) On the other hand, thanks to the comparatively recent "movement" of postmodernism, the trend in Western literature agrees (for now).
So, in my opinion, how does a bad fiction writer end a story? Happily, I tell you. If you care at all about realism (and you definitely don't have to) I would advise you end your masterpiece on a flat note--one neither particularly happy nor sad.
Reading is not a passive activity. When one is engaged in reading, there are a seemingly infinite number of things upon which to ponder at the end of the adventure. There's nothing wrong with leaving the reader upset--or even downright perplexed--as long as it is done skillfully and plausibly.
Pontification
This leads me, rather eagerly, to the next point. If, through the entirety of your narrative, you have revealed nothing of your character's intentions or the plot of the story for the sole purpose of impressing your intended reader, you are pontificating. Please. Stop. There is nothing more annoying (and boring) for an editor to read than a dissertation on philosophy of mind told through two guys sitting in a cafe using elaborate and unnecessary vocabulary.
Save that for academia.
Now, don't get me wrong. Figures such as Sartre, who write out their philosophies in the form of prose create intriguing worlds in which to delve. Novels/stories requiring a second read to gain more insight into the intricacies of the language used or a plot element are rewarding to readers. Stories requiring several hundred reads with no epiphanies--are merely examples of the writer's superior intellect and complexity of wit. Right...?
On that note, this editor has noticed on several (hundred) occasions that literary pontificators tend to use long sentences to get across the points of the story. Please. Stop. That kind of sentence structure was allowed (and necessary) in years prior to the twentieth century. Now, however, at the beginning of the twenty-first, with the aid of technological advancements such as color photography and the internet, a reader does not need to be told what something like the Eiffel Tower looks like. She probably already knows. Seriously, sometimes less is more...
