Speech
When they say nothing also also says something about them. When they avoid talking about a crime, could be guilty!
Speech also matter how they say it.
Characters vocal tone, speed, cluttering tells much about a character. A rich person speak clearly and arrogantly. If someone hesitates, he is unsure or lying.
Thoughts
A person's thoughts tells about the person. Monologues are used in plays and movies to expose thoughts. (Self expression). Thinking is based someones beliefs and values.
Emotions
Emotions are outcome of internal thoughts. Emotions expose someones inner feelings. Emotions most expressed in body language and voice tones. Crying, Anger, Looks, Postures Feelings expose emotions of the character. Emotions are results of external effects on characters personality and personal goals, ambitions and aspirations. Creating emotions creates emotions in audience. It is the essence of a story and your plot.
Effects on others
The interactions with others shows a great deal about a character.
Personal, Social and Business interactions may based on empathy and social understanding. The effect on others shown with reactions of others to a character. It says a lot about them. Are they friends or enemies. They they care for each other or not?
Actions
The actions of the character is driven by their inner feelings, how they react to a situation and relationship with other characters they are interacting with. A mother will blame talented daughter and praise some one opposite. A may boast about favourite teacher and bully an innocent girl. From the actions the true character emerges, like in real world.Actions under stress changes a person. Stress is test of personality and help audience reveals more of the character.
Looks
Looks of a person exposes the character. Yet appearances can be made deceptive in characters. A person may look like a girl to gain access to girls school. Looks are not only dress. Facial expressions and body language reveals intentions of the character fear, happiness and loneliness are shown from eyes. Looks also created with dress and outfit. It can reveal social class, occupation, locality, values as well as sense of passion.
The characters that appear in stories described 2D or 3D. The 3D character is more realistic. The 2D character is flat and relatively lifeless.