Your problem is that you're trying. See, you can't show you're interested. Except enough to make them make the first move. But not too much, y'hear?
Like Dekker said, play it cool.
I used to think that way. Perhaps I grew bitter over lost chances and failures. Perhaps I grew cynical about relying too much on the intelligence and perceptiveness of others. Or perhaps it was the long-delayed understanding that the first time out I had been betrayed, the death of some kind of innocence.
I wasn't able to eliminate the gentleman from me, and in real sense I don't really want to try. He has his place, and it's important. But the timidity that accompanied him, the method you describe, won me nothing and cost me much. Too many chances slipped through my fingers. So I changed my tune.
"This is what I think. You're interested, you know where to find me." I just say it. I do nothing else, go back to my own whatever afterwards, but say it, no hesitation, directly. After that nothing more comes of it unless I get a response. I'm told I come across as having complete self-confidence. This isn't true. It's recklessness. I don't expect most people would be able to handle that approach; I've suffered enough that I no longer care if I do so again. I've been there and done that and I'll live. Better to fail through action then inaction.
And you know, it's worked more than once. What comes after, that's another matter. But it got me where I am today, thinking about giving someone a ring, so I think it's worked pretty well.