Define the purpose and scope of the girl you want to build
Choose the core traits, values, and personality
Design the physical attributes and appearance
Set the age, background, and life history
Create the interests, skills, and habits
Establish the emotional range and behavior patterns
Write the voice, dialogue style, and mannerisms
Add strengths, flaws, fears, and motivations
Build relationships, friendships, and family connections
Determine the setting and social environment
Refine the character through testing and revision