As I revise my novel, one of the things I'm noticing is that I'm often amplifying character reactions and behaviour beyond what they'd be in ordinary life. It's not that I'm trying to create an extraordinary character. (Though I suppose all authors want to think of their characters that way on some level, or else why would we bother writing about them?) But using words to shape personality involves making judgments about what is important for the reader to know, see or feel and then writing to emphasize those elements.
To bring out a character's personality, I think it's important to sometimes make their reactions a little over-the top. Give them a dramatic flair. In the same way that writers pile on more and more impossible obstacles for a character to struggle through, the actions and reactions of the character need to be big and bold to show that they are up to the challenge. Being bold doesn't mean that characters can't be quaking in their boots or feeling timid in the face of danger, but their fears or lack of confidence need to be big enough, noticeable enough, for it to stand out to the reader.
Some tips for making characters more dramatic:
1. Create a character that is conflicted to begin with. If there is something about the character that sets up an inner conflict, it can create empathy even before the story gets started. A typical example in a middle grade or YA novel might be having a character with a parent that recently died or moved out. Or some type of disability. Even if that's not what the story is going to be about, there are underlying emotional issues to resolve and that creates more drama.
2. Have secondary or minor characters react to what the main character is doing. This draws attention to the reaction or behaviour for the reader. If the other characters think it's important, then it must be important.
3. Choose the reaction with the most impact and let it stand on its own. Write all about how the character acts, thinks and feels when reacting to an event in the story. But then go back and choose the most compelling way to describe it and cut the rest. Over-explanations take away from the dramatic impact. But watch out for the opposite problem too, where the reader doesn't know enough about what the character is thinking and feeling to care. It's all about balance.
How do you make your characters more dramatic?