How to get girls to like you?

I'm just wondering what I should do to get a girl to like me or to show them i'm a good guy. My situation is that I have a girl friend I really like & she knows it. I've liked her for awhile but it seems that i've gotten friend-zoned hahaha. She sees me like a brother at best (guys you know how that feels haha). She can like a lot of guys at one time & i'm fine with that but I wanna be one of those guys & have a shot with her. I did flirt with her before & it was leaning towards my way but then she really liked one of my bestfriends & A: I had no chance at that point & B: He like a brother to me so I couldn't like that while they went out & liked each other. Now they've broken up & they don't like each other anymore so thats not a problem anymore. I just wanna know what it takes to get a shot with her. Oh & by the way she really likes this other guy now but I'm not his friend cause I try to be his friend but he is a d-bag. Thanks in advance for answering or if you clicked on this haha.