Conquering a girl's heart is a big art! That's why men can be divided into seducers and those, complaining of women's attention absence...
To be the first type, I would like to give you a cool idea! It will work without failure!
To make it you will need help of your friend.
Buy a beautiful rose and pass it to your friend beforehand. During the walk with your girlfriend, start kissing her - go on for at least 30 seconds. At that time your friend goes by and unnoticeably passes the rose to you. Kiss her for another 10 minutes, while the friend will move away. Then release her from your embraces and gift this rose to her! Only imagine her surprised face, coz the rose appeared from nowhere for her...
Go on your walk. In some distance she will be again greatly pleased. While your girlfriend is busy, asking you about rose, your friend should hang or attach a poster to a tree or something like that, reading for instance: "Nelly, Mike is crazy about you".

These romantic things will