Give the girl a soft toy in the form of a mournful elephant, or Hippo. Do not forget to add that you are the same strong, but the same defenseless in front of her. Maybe you will regret later and will forgive.
Remember that your reasoning and arguments are logical and women more emotional. So in a conversation with her, do not focus on logic, more talk about feelings, relationships, more likely to remember some pleasant moments which you are associated.
Tell her compliments. As you know, the woman likes ears. Just do not overdo it too complicated epithets can be mistaken for a banal joke or she just won't believe you.
Giving her flowers. With or without. Bouquet does not have to be expensive and elegant, even the smallest, accompanied by a kind word, can do wonders. Perfect bouquet that you have collected personally.
Realize some of her dream or desire. It is better that it was what she mentioned as if in passing. She will know that you listen to it, and therefore, it is really important. For example, she once mentioned that she would like a handbag, a book, a bracelet. So think hard and try to realize her desire in life.
Discuss it with even the smallest aspects of your relationship. Show interest, keep the conversations on any topic, which in any way disturb her. Let's her to speak first, and then start to speak for themselves. If she asks for advice, may it be an advice, not a lecture. If she wants to talk about that it is not satisfied with something, listen to it carefully and try not to yawn, even if you are very tired.
Play with her hair and hug her as often as possible. Hugging, hold her to him as the most precious thing you have. More touching, stroking and kissing.
If you know that she values the opinion of his mother, and you have a good relationship, ask them to assist you. Explain how important her daughter is to you. Try to get the mother to his side. And she, in turn, I will find the right words to explain her daughter what a good guy and how it would be foolish to lose him.