with honesty and respect
Like how he'd like her mother to be treated by his father. How his sister be treated by her lover. How his daughter be treated by his future son/daughter in law.
Like his best friend and he should put your needs before his own
First of all, he'll take U seriously & do mistakes...If he's a gentleman, he'll respect Ur dignity so much than usual...
He should be true to himself and reveal his real self so that the girl can decide with good and accurate information. I see it as a form of dishonesty to pretend to be something other than yourself until you get married, and then revert.<br />
Though, more directly, with respect. He should spend time with her, doing somethings together and supporting her, doing some things apart. He should do things that would build the relationship.
Let the world, enriched with wise men and well respected women tell her what you are.
With love and respect, as partners, and generally the same way he would like to be treated by her.