It’s a wonderful idea and a useful tool for your writing.
As an exercise:
Take a moment to consider your main character. What kind of heart would they have? The heart of a warrior? A Salesman? A Doctor? Now decide what things make up his/her heart. Is their family most important to them? Their job? Their legacy?
By deciding who your character is and then what makes them who they are, you can learn important information to use in your story.
Complete the exercise for your villain, mentor, sidekick and other characters 🙂