Maybe for a start, get to know what she really likes and hate,
and try to think what she really thinks, communicate with her...
Act on her likes and dislikes and give some surprises once in a
while when she least expects it... For example, if you can remember
when was the date that both of you were together as an item, spring
her a small surprise maybe a dinner plus a movie and walk her home,
at her doorsteps, kiss her and tell her "I love you"... 