[ADULT] effectively communicating sexual intent?

[Rezzy7]

In the past when I'd meet someone it's been up to the fates, luck, or the girl chasing me, that decided if anything progresses romantically or sexually. But those ways don't allow me any say in the matter (save for if I decline), and meanwhile a lot of time can go by.

I think it's partly from not conveying interest well, or somehow doing so in a way that's a turn-off (like showing too much interest). From what I have gleaned touch is important, and also the flavor of flirting. I understand the touch part, but maybe not the flirting, especially when it becomes more sexual. I've just never been in enough situations to piece it all together by trial and error.

I guess there's a way to gauge what is acceptable conversation to her, but maybe I haven't learned this. Everyone's different. How do you know what is effective and acceptable?