10.  The format is incorrect. 

        Luckily, I don’t see this as often anymore, but I still see it often enough that it needs to be mentioned.  And it’s actually several problems lumped into one. First, some people still use the incorrect manuscript format.  I won’t go into the details of correct format here since most of you should have it down pat, but in case you don’t, check out my format article.
        Second, some fail to make the synopsis the correct length, meaning it doesn’t meet the length requested by the agent/editor/contest.  To fix this, do your homework.  Most editors, agents, and contests have detailed guidelines that explain how long your synopsis should be.  Get a copy of those guidelines (or call and ask), then give them the length they ask for.   I know of a few agents who won’t even look at your submission if you send them a ten page synopsis when they’ve requested no more than four.  Don’t shoot yourself in the foot this way.
        Third, some writers write the synopsis as if it were a term paper outline, telling us in boring, line by line detail everything that happens in each chapter.  In a good synopsis, the writer tells the story as if he were relating it to a friend across the dining room table.  Don’t explain every scene—just hit the high points and make it sound as interesting as your story.

9.  The synopsis concentrates on the first three chapters of the novel.

        This problem occurs when the writer finishes chapter three and decides it’s time to write a synopsis and send it off to a contest or editor to get some feedback.  Since the novel isn’t finished, the writer elaborates on the completed portion of the story to the detriment of the rest, so that 75% or more of the synopsis covers what happens in the first three chapters.  To fix this, do some hard thinking about your story and flesh it out fully before you send it out into the world.

8.  The tone is inconsistent.

        I’ve seen some synopses with widely varying moods that do nothing but confuse the reader.  For example, the writer might start off describing a horrible, angst-filled character background, then segue into a humorous romp.  It leaves the reader baffled, wondering what kind of story it really is.  So, make sure your tone is consistent throughout the synopsis—and that it matches the tone of your novel.

7.  The writer speaks directly to the reader.

        Here, the writer inserts comments in the synopsis that address the reader directly to ensure the reader "gets it."   For example, she might write, "The conflict is..." or "At this point in the story..."  Resist this urge.  Talking directly to the reader jerks him out of the flow of the story.
        Or, the writer might tell the reader how to feel by promising the story is heartrending, humorous, exciting, etc.  If you tell the reader how to feel, you run the risk of putting his back up.  Quite literally, the reader will be the judge of whether your story makes him feel the way you intended.

6.  The synopsis ignores market considerations.

        In this problem, the writer forgets to show how the story fits within the targeted genre (e.g., she leaves out the development of the relationship in a romance or forgets to show all the clues in a mystery, etc.).   There are certain expectations for each genre and you need to ensure these expectations are met in your synopsis or you run the risk of it being rejected.
        For example, in a romance, you must show the development of the relationship.  I can hear some of you saying, "Duh!" but believe me, many people leave it out.  They get so caught up in the external plot that they forget to show how the romance develops.  This may include such important steps such as the lovers’ meeting and attraction, their first kiss, the time they first make love, the moment they realize and/or declare their love, and their final commitment to each other.  Make sure you show when these pivotal points happen in the synopsis.

5.  The synopsis lacks emotion.

        Often, writers will show the development of the plot, point by point, but forget to explain how the characters feel, react and change as a result of each plot shift.  Since most people read novels for the characters, they want to know how the characters think and feel about what’s going on in the story.   So, if something devastating happens to the heroine, show us how that changes her reactions to her goal, to the other characters, or to whatever else is important to her and the story.

4. There is too much detail.

        Sometimes the writer gets so caught up in the minutia of his intricate plot, fascinating research, historical period, or speculative world that the synopsis is stuffed with irrelevant details and characters.  In the synopsis, we don’t really need to know how a spinning wheel works or what a minor character looks like...unless it is a key element necessary to understanding the plot or the major character(s).  Save the details for the story itself—and include them there only if they’re relevant.  Don’t use your novel as an excuse to show off your meticulous research unless you really want to bore your readers.
        A related problem is listing all of your twenty plus characters by name.  In a ten page synopsis, that’s a lot of names to remember.  Just mention the names of the key protagonist(s) and antagonist(s).   Don’t mention secondary characters by name unless they show up several times in the synopsis.  Instead, refer to them by function or relationship: the cab driver, the housekeeper, Sarah’s daughter, Joel’s boss, etc.

3.  The synopsis leaves questions unanswered.

        This is when the writer leaves out key character motivations or forgets to tie up loose ends of plot and character development.   It also includes the unpardonable sin of telling the editor she has to read the whole story to find out how it ends.  Do this only if you want an immediate rejection.
        Though it’s difficult to figure out what to put in and what to leave out of the synopsis, make sure you at least show us the resolution of the main characters’ goals and conflicts, and the resolution of the plot at the end.  If you’re unsure if anything is missing, give the synopsis to someone who knows nothing about your story and ask her to tell you if she has any unanswered questions after she reads it.

2.  The characters aren’t interesting or sympathetic.

        Here again, the writer has concentrated so much on the plot that the characters haven’t come alive.  To fix this, use Debra Dixon’s Goal, Motivation and Conflict method and make sure you explain what your major characters want, why they want it, and what’s keeping them from getting it.  Then at the end, show how they have grown as a result of the story.  That will help make your reader care about what happens to them.

1.  The synopsis lacks transitions.

        Even when everything else is done correctly and all the plot and character elements are included in the synopsis, writers often tell their stories with a series of unconnected declarative sentences: She did this.   He did that.  They left.  It makes for disjointed reading and interrupts the smooth flow of the story.
This is the problem I see most often.  Writers who use transitions with ease and skill in their manuscripts somehow still fail to use them in their synopses.  The objective is to make your synopsis flow as easily as your manuscript, to make the story so interesting that the reader will continue reading without a hitch from beginning to end.   So, connect those ideas from one sentence or one paragraph to the next to show how each plot point and character change are related to one another and affect what comes next.  Even if you have to use such phrases as "Meanwhile, back at the ranch..." or "What Harold didn’t realize was...", it’s worth it to make your story read smoothly.
        Take the example above: She did this.   He did that . They left.  How would you make it flow?  Perhaps you could say: When she did this, he grew angry and did that.  Furious at each other, they left and went their separate ways.  In other words, if you use character reaction, feelings, and motivations to connect your sentences, your synopsis will not only flow smoothly, but your characters will come alive.