Falling in love with your best friend is very common though awkward in most cases. I understand how you'd want to take it up a notch rather than just coming out and telling him that you love him. Being subtle about things like this is good. What I would do is plan something with just the two of you. I assume that since you guys have been friends for a long time, you probably hang out with other people a lot. So hanging out with just each other would draw some attention to you. Go to a movie with him, or out to eat. And instead of giving off a "just friends" attitude, act a little more serious towards him. Put your hand on his leg. Give him a warm hug. Little things like this really speak for your feelings. He'll get the hint! Good luck!