There are different components that make up a story. Each part is incredibly important. When you are brainstorming it is a good idea to focus on each part separately and then put it all together! It's as easy as 1...2...3!
1. SETTING: The setting is the time and place of the story. The time includes the year, the season, the day, and could be even as specific as the time of day. The place of the story is where it is located. It could be as general as the planet or as specific as a particular address.

"When you are thinking about the setting, try to make a list of all the different time periods you would like to write in. Then, make a separate list of all the places you would like to write about. Try mixing and matching your ideas, thinking about the different places with the different times. You might think of a good idea you wouldn't have thought of otherwise!"
2. CHARACTERS: The characters are essential because they make the reader care about your story. The reader wants to see what the characters will do and what will happen to them. Characters that are most interesting are ones that are developed. To develop a character means to give them a personality, hopes, fears, and unique traits.
"One fun way to brainstorm a character is to think of a name first. Then write down all of the things you associate with that name. You will have an idea of how you might want to develop the character and what role he or she will play in the story!"
3. PLOT: The plot is the action of the characters and the major events of the story. What will happen in your story? Why are you writing it? The plot usually has a beginning, a middle, and an end. It usually has a climax, the part of the story which is the most exciting, the part that to which all of the suspense builds up.

"The best way to think of an exciting plot is to think about the climax before you brainstorm the beginning and end."