With fiction, endings are the one time where you can allow yourself to linger (within reason) over an extra sentence or paragraph. While beginnings have to hook, and middles must be tight and well paced, endings are to be savored. Readers who have followed with interest and anticipation the adventures, exploits, and travails of your carefully and lovingly crafted characters want to relax into the denouement and relish the hard-earned finale. An ending which is too fast or too abrupt is more likely to dissatisfy than one which is too leisurely.

A good fiction ending:

• Lets readers know that a story is done. They shouldn't need to see "The End" or have to check whether there's another page to know that the curtain has come down.
  
  
• Tells the reader everything they need to know. Plot points are wrapped up, characters' fates are resolved, and all questions are answered. An ending which leaves readers scratching their heads, wondering "But where did the magical sphere of statistical manipulation that saved the day come from?" or "What happened to Bob from scene 2?" or worst of all, "Huh?" needs to be rewritten.
  
  
• Happens shortly after the story's climax. Once you reach your resolution, that's the end. Don't be tempted to show how everything returns to normal a couple weeks (or months or years) later. Doing so dilutes the sense of closure the climax provides -- in short, it's anticlimactic. If you find yourself needing to write another paragraph, page, or chapter in order to wrap things up, then you might have to rethink your resolution.
  
  
  • If you feel that your story requires an epilogue, it should be set in a new place or time. An epilogue occurs after the events of your story are over as a supplementary second ending. It provides something new, an unrevealed consequence, or additional insight. An epilogue is not a proxy ending or a reiteration of the finale; your story should still be complete without it.
  
  
• Demonstrates how your character(s) changed over the course of your story. A meaningful story affects its protagonist as much as he or she affects it. Without evidence of character growth, readers often come away asking themselves, "What was the point?"
  
  
• Surprises and/or provides an unforeseen revelation or a fresh perspective. This is not the same as pulling a solution out of left field or introducing a deus ex machina. The best surprise endings are ones that leave your readers with an "ah hah!" moment, that make them think "I didn't see that coming, but I should have!" It should be carefully foreshadowed, consistent, and credible -- enabling a minority of careful or exceptionally perceptive or sophisticated readers to predict what will happen -- but still be able to genuinely catch most readers unaware.
  
  
  • Avoid cliché "surprise" endings such as:
    • And then I woke up/it was all a dream.
    • And then I died.
    • And now I reveal to you that I'm actually an alien/ghost/vampire/etc. or I found out they were an alien/ghost/vampire etc.
    • And they were called Adam and Eve (or other "Shaggy God" twists).
  
  
• Makes a strong statement, either positive or negative, but never wishy-washy or weak. Even if that strong statement is, "You must decide for yourself whether this outcome is good or bad," don't vacillate about it.

In articles, essays, or how-tos, the ending should be a conclusion, not a synopsis or a reiteration of what's been gone over before.

A lot of nonfiction simply stops after the information has been presented or trails off, uncertain what to do once all the important points have been covered. This is because nonfiction writers and journalists are often told to organize their information so that the most important and interesting items are presented first -- in order to "hook" readers and because it's assumed that most people won't read to the end. However, this perpetuates the prevalence of weak (or nonexistent) endings in a Catch-22. Weak endings provide little incentive for readers to keep reading, so they don't, which provides further evidence to editors and writing instructors that readers stop before reaching the end.

However, as writers for young readers, our goal is to instill a love and interest of both our subject matter and reading in general. Boring our audience mid-article such that they have no interest in finishing is no way to impress them or editors.

A good nonfiction ending:

• Wraps all the information presented into a meaningful package for the reader, demonstrating to him or her the importance of what was presented. It ties everything together and provides resonance with a young person's world.
  
  
• Evokes further interest and encourages curiosity, questions, and subsequent reading or research.
  
  
• Doesn't repeat prior points. It may echo the beginning in order to provide closure, but in doing so, it also offers new information that allows the reader to join everything presented into a coherent whole.
  
  
• Doesn't sledgehammer a message to readers. Trust yourself and believe in your work enough to be confident that your writing successfully conveys your point and says what you intended for it to say without having to bludgeon your readers with it at the end.

An article that appeals to young readers (and editors) will be interesting, informative, and relevant from start to finish. Likewise, a good story resonates with readers, leaving them with a sense of satisfaction as well as something to take away from the experience.