Create unique characters by setting them apart from the rest.
How they look and sound is a good starting place, but you need to dig a little
deeper and give your characters character.
Every character has past experiences, strengths, and
weaknesses that make them who they are and drives their behavior. If your character is a manipulator vs. flamboyant, their actions and dialog will look significantly
different. One is self-justifying, while the other is self-blaming. One is aggressive, while the other is indirect.
Try to avoid clichés. Creating a nun who’s compassionate isn’t very
interesting, but creating a nun who’s compassionate AND depressed, OCD, anxious,
or ADHD, could add an interesting twist or comical relief.
For my birthday, my daughter bought me the book Writer’s Guide to Character Traits, by Linda N. Edelstein, Ph.D. It’s been a fascinating read as I delve into the personalities of my characters. I find it also makes writing easier because I have a better understanding of who my characters are and what their internal motivations might be.
Stories are about journeys: to get, to find, to reach, to achieve, to overcome. Within that physical journey there needs to be a personal journey as well. Characters need to grow and evolve. Perhaps the dependent learns to be independent, or the victim learns to stand up for themselves. Without growth, there's no resolution; your characters will fall flat and irritate your audience.
By taking the time to sit and identify each character's character, you'll be able to create more authentic scenes that ring true with your audience.