Have you ever searched for the right words to describe your character?
Whether they be protagonist or antagonist, some of the best traits are found in ourselves.
Selfishness, greed, the rage at being at the back of a long line. Forgiveness, self-depreciation, charity. We all have traits and moments where we embody the worst and the best humanity has to offer.
Every character you create should have a well-rounded personality, with good and bad intentions. It is their goals and how they achieve them that makes them good or evil.
Try looking inside yourself for your best and/or worst traits, amplify them, what kind of character does it create? Maybe you have found the arch-nemesis for your story, or a deity worthy of building your world around.
Exploring the depths of our world, our histories and our emotions can bring so much to the surface. You can use it, create something new from it or even heal your own emotional scars.
Dig deep, bring it to light.