When readers invest their time into reading a story, they expect to be rewarded with an ending that is satisfying but thought provoking. If the readers don't get that ending, they feel slighted and disappointed. Your ending needs to answer questions but create new questions while you're at it. Here are some great ways that will end your story with a flawless finish and make it seem natural to your story.
[1] The Inconclusive Ending
Now all stories leave the audience hanging to some extent but in this case the ending would have a cliffhanger approach that could lead to a sequel... or not.
You must be very skilled and strategic with this technique as it causes you to look lazy or unable to come to a good close if you're not careful. It needs to be able to provoke the reader into thinking "what happens next" after it's over.
[2] The Big Twist
These ending are popular when they are well written. To make it work you must pull all the plot lines together in a conclusion that is surprising but believable. To make it work it would be a smart idea to drop subtle clues throughout your story that could provide hints to your characters' future actions.
[3] The Everyday Ending
Not every story needs a big BANG at the end. The everyday ending is similar to the inconclusive ending, except with more detail. You should leave the characters in a setting or situation they've been in all along, but include details that clue the reader into what will happen in the future. Doing this, the characters' fates are not extraordinary, they'll simply live their lives in the same manner, if not slightly changed from the events in your story. To make this successful, somehow confirm and fulfill the characters personalities in a way that's consistent with a real life scenario.
[4] The Epilogue Ending
This is the scene that is removed from the story in both setting and timeframe. You can have the readers revisit the characters weeks or months after the climax or a generation into the future when their children are grown up. Either way, provide details to what has happened "in the meantime" to give your readers what they're looking for.