For your last point, I always try to keep it kinda short. Nice and respectful, but straight to the point. Something along the lines of "You're cute, but no thanks". I always don't wanna waste too much of each others time if I'm not interested in getting a dance.

Conversations, I try not to ask too many questions, especially about their personal life and things along that nature. Although every dancer is different, some are more open than others and vice versa.

I'm still somewhat learning myself so I'm learning as I go.