How can I contrast the characters of Romeo and Juliet?

The greatest contrast between Romeo and Juliet is found in the circumstances that we meet both these characters in. When we first hear about Romeo, it is his parents and his cousin, on the street, discussing him. Romeo's parents ask Benvolio what the cause of his sadness is. They then exit before Romeo approaches. Romeo and his parents never share a scene together until the end when his father discovers his dead body. So, from that we can assume quite a bit about their relationship. 

Conversely, when we first meet Juliet, her presence is being requested by her mother. She is safely tucked away in her bedroom, and obedient to a fault to her mother's wishes to consider marriage to Paris. 

So, Romeo is on the street avoiding his parents, and Juliet is in her bedroom agreeing to her parents' wishes.