Character: You at least need a main character or protagonist. And yes, you can have more than one main character. Dual timelines remain very popular and many well-regarded stories explore the points of view of more than two main characters. This is especially true if you’re writing a novel versus a short story. My one piece of advice? Try not to repeat the same scene, showing it from different characters’ viewpoints. This can end up frustrating your readers and making them impatient.
If you have a character who is adverse to your main character, they might be an antagonist. Sometimes the antagonistic force isn’t another character, but another sort of obstacle standing in your main character’s way—or even a force of nature, such as an approaching storm.
Pacing: the speed at which your plot unfolds. A quiet, literary story may have a contemplative pace whereas a mystery or thriller is going to be a page-turner that rarely slows down.
Plot: Something has to happen to your character or the reader will become bored. The plot draws the reader into your characters’ lives. Plot is the bouncing ball, the up and down, of the narrative. Your main character encounters obstacles, learns lessons, and gets closer to, or further away from, her goal.
Setting: Where does your story take place? Of course, difference scenes are likely to have different settings. Give some thought to how setting might impact your characters and plots. Why is the story taking place here? Time period is closely related to setting. Are you writing historical fiction, contemporary, or speculative (set in the future)?
Theme: What are you trying to say with this piece? I tend to favor themes that emerge organically. Otherwise fiction can feel forced or preachy.
One of your goals as a fiction writer is to weave these essential elements together to make a cohesive whole. This involves asking yourself a number of questions as you write. Have I selected the main character with the most dramatic story arc (i.e., the character who changes the most)? Why is this particular setting the right one? What does this time period mean for my main character? Does the story’s pacing help or hinder the emergence of the theme? By keeping these questions in mind you are well on your way to crafting a multi-layered story that will keep your readers’ attention.