If your characters don't come alive in the script, they won't come alive on the screen. Answer these questions, as you characterize the protagonist and other characters within your storyline: what is this character's goal or motivation, why does he or she want to achieve this goal, who or what is trying to stop this character from reaching this goal and why, what strengths or weaknesses of this character will help or hinder in the pursuit of this goal?
Realize your character with all six of your senses, react to him or her with your emotions, be able to follow the character with your mind. Fully breathe life into characters by covering their ancestry, past life, environmental influences, occupations, future aims, physical appearance, emotional drives, and basic unique traits. Get inside his or her skin; become the character.