Characters. Without them no work of fiction, cinema or theatre would exist. But how do we choose who to put into our stories, and what makes us choose them?
People in general are fascinating. Everyone is different due to a variety of factors, environmental and genetic. It's important to remember that when creating imaginary people to populate the worlds we create in out heads. Even within single families you can find a range of different temperaments and personalities. As writers, we need to be able to paint these differences, use them to create conflict and dynamic in our work.
It is important to give every character flaws, big or small. Nobody in real life is perfect - seriously, can anyone tell me they've met a perfect person? And besides, perfect is boring. Flaws are beautiful in their uniqueness and the various perspectives they can give on the world. Without flaws, our characters will have nothing to overcome and will not learn anything over the course of their journey. Because yes, to satisfy an audience, by the end of the story, characters do need to have changed, even if the change is subtle.
In order to create real, rounded characters, it's important to focus on small details to breathe life into them. Give them quirks, habits or mannerisms that show who they are. It's not enough to tell the reader a character is shy. Show it by having them shake their hair over their face whenever they're around people, or tug their sleeves down over their knuckles to hide the fists they've clenched in discomfort.
I spend a lot of time watching people. I love to sit in public places and study the way people act and move and react. I store details in the back of my head so when I need an specific quirk or reaction, I have something authentic to put in place.
What do you do to ensure your characterization is realistic?