Create characters with good physical descriptions for a good mental picture. The main character is the one that will determine which way the plot turns. The main character(s) should get to the bottom of the mystery. The main character may make a mistake and get tangled into the plot. Other characters such as a perpetrator, a victim, a detective, and/or an assistant are important to the success of the story.  They should be believable characters and each of their roles should be carefully planned out.
 

Provide a vivid description of the surroundings in your story.  Make the readers feel as if they can close their eyes and picture just where the scene is taking place.  Create interest and excitement by providing unusual settings for the events of the story. The setting should have a suspicious feel to it, like a dark character is lurking around the corner.
 

Begin your mystery with action and suspense. Something exciting should occur. You need to create a plot or a storyline telling what the mystery is about right away.
 

Every mystery has a problem to solve, like who committed a crime or where something is hidden.  The fun part is leaving clues for the reader so he or she can put the pieces of the story together like a puzzle.  You can be tricky and put "red herrings" into your plots that will put a little more mystery into your story by throwing the readers off track.  This forces them to sift through the clues and decide which ones pertain to the solution of the problem and which do not. It also makes it more interesting if more than one person is the suspect.
 

The solution should be believable.  In order for the story to work, all of the clues have to be included in the story.  You cannot have unknown surprises that no one would know about.  That would not be fair!