Not a simple questions you've got here my friend, making sure you pick that one girl with the mini-skirt without pantys helps for sure. I've had the pleasure to meet her once in Cancun, crazy shit going on there so going to Cancun may help to.
Once you found her it's easier to dance from behind her, it's a more natural position to fuck and dance at the same time and less obvious you're boning her that way to. Good luck!