1) Characters should serve as foils to one another. This provides conflict and distinguishes them as individuals. This is because characters are often defined by who they are not as well as who they are.
2) If you want your readers to empathize with your characters, they should be relatable to the audience. One such character, known as an ‘audience surrogate,’ knows about as much as the audience does. A prime example would be Watson from Sherlock Holmes stories.
3) Try observing how people act in social situations; sometimes it helps to base a character around a person you know. (But don’t make it apparent enough that they get offended.)
Likeable character traits: Beauty, courage, wit, cuteness, passion, patience, innocence, youth, nobility, leadership skills, empathy, and opposition of the immoral.
Disliked character traits: Flat or static characters, wish-fulfillment characters
Other character traits
Age/Date of Birth
–Choice of Attire (Accessories/Piercings)
–Scars, Birthmarks, Calluses, Tattoos, Wrinkles
–Use of Cosmetics
Country of Origin
Medical Background (Illnesses, fractured bones, chemical imbalance, poor eyesight, etc)
Relation to Others
Social Security Number
–Type of laughter