You have to be able to verbally stimulate the readers senses and explain the kind of setting you or they are in depending on what POV you're writing in.
taste touch sound hearing seeing
Okay so for example:
Wrong: The castle was beside water.
Right: The waves crashed loudly against the shoreline. The fog lifted lightly and the medevil castle came into view.
You also have to make it intriguing at first kind of, like an essay. Also include a decent plot, like a movie but more detailed.
I hope this helped.