We're often told that the characters in our novels must grow and change. But how do we plan that growth when we're outlining our story? The easiest way is to design a character arc for each major character.
A basic character arc will look something like this:
1. Emotional Wound: Question: what has damaged the character? Answer: His father abandoned him as a child and he doesn't know how to love anyone.
2. Inner Goal: Question: What unconsciously motivates the hero? Answer: His inner need to be loved; the growth he must undergo through the story is that he must learn how to love someone else before he can believe that he is loved.
3. Character Flaw: Question: What stops the character from reaching his inner goal? Answer: He is unable to trust that someone else will love him enough to stay.
4. Turning Point: Question: What happens to make the hero begin to change? Answer: He meets a woman and falls in love.
5. Black Moment: Question: What makes him believe all is lost? Answer: He sees the woman kiss another man and climb into a car with him and thinks she is abandoning him.
6: Climax: Question: How does the hero take action based on his inner changes (refer point 4). Answer: He decides to ask her for an explanation, where before he would have never spoken to her again.
7. Resolution: Question: How is the conflict resolved in such a way that the character's inner changes have become permanent? Answer: He drives to her flat to speak to her about what he saw. She invites him in to meet her long-lost brother who is the man she was kissing. The hero - relieved that he had not just walked away - shakes the brother's hand and asks her to marry him. They live happily ever after.
For more complicated stories, the character arc becomes more complex. For example, in a tragedy the hero would not experience a "black moment", when everything seems lost but then turns out fine (because of his inner growth has changed his behaviour). Rather, he would experience a moment when everything seems as if it will turn out fine but, in the climax that follows, his fatal flaws (those that he has not been able to overcome) will bring about a tragic resolution.
Drawing up a character arc will help you create more compelling characters who grow and change as your story progresses along the twists and turns of your plot.
You can read more about character arcs here and here and here.