In each story, the characters must have a reason for being. This reason drives how the character thinks and behaves, speaks and listens. The ways in which the main character interacts with others, whether animate or inanimate, affects the development of the story.

In order to incorporate the unique personalities of your characters, you should develop a Character Arc for each of them before you begin writing.

What are the components of an arc?

1. The character is going through life, everything status quo, until an inciting incident shakes things up. It could be meeting the future love of her life, having something stolen, being injured in an accident, or going on a trip. Something has to happen that reverses the world in which the character knows and feels comfortable living.
2. The character must want something. This something, in the character’s opinion, will restore balance to the known world. Think abstract as well as concrete.  If it’s love that he wants, how badly does he want it? How hard will he work to find and keep it? What if it is a precious family heirloom? Where is it, what obstacles must she overcome to get it, and is she willing to put forth the effort to possess it?
3. In the search for this something, what complications arise that keep the character from obtaining it? There should be a series of complications that occur, not just one. These are the events that give rising action or tension to the story. It’s the equivalent of taking baby steps. For each few steps forward, a roadblock appears that sets the character back a bit. Make sure that the complications are realistic and severe enough that the character feels a level of distress.
4. In the search for the desired object, what conflicts with other characters arise? Perhaps a sibling already has possession of the heirloom and won’t give it up. Or someone else is dating the love of his life. Think about the dialogues that ensue, the feelings hurt, maybe even injuries that occur. How does the character react to each of these altercations?
5. At the end of the story, has the character obtained the object of desire? Not all stories end happily ever after, so there is no need to have the character succeed. There can  be partial success. Say, for example, that the family members agree to share the heirloom, or to give it to a different relative so that neither one possesses it. Or that the couple can’t make it to the engagement and marriage stage, but agree to remain best friends. In both cases, the character has not truly succeeded in his quest, yet there is resolution.

Your next assignment is to create a character arc that encompasses all these conditions. You may have to write several versions until you come up with one that works.