How to get a girl to like u?

Look I broke up with my g/f a year ago, and we were 11 at the time and had been going out since ten, now we are 12, and I still like her. How can I subtly show her that. I don't want to just say it. I want to be cunning. We are friends now. What should I say, that's let's her no. I also want her to like me more. Is there anything I can do to build trust.