Well what works for me and i've used it for the last 3 years now, when I realised that going up and asking a chick to dance was lame :p
what I do (after I have made eye contact or opened up the sceanrio), is I will smile keep eye contact and kind of tilt my head down a little while maintaing the "Bedroom eyes " then in a non-threatening manner slowly raise both my arms and hold them out to her (a little under shoulder height, but a angled downward, and kinf of let my hands fall, for me they ALWAYS place their hands face down on mine.... Then in a NON-SLEAZY way I gently(but authoritively) pull them close to my body ( doesnt matter what music-the more unconventional the better), then as they get within a few centimeters from my body i keep hold of their hand an push them back in a twirl, then u bring them back in, then a half turn usually gets their back flat against the front of ur body ........
then I will usually smell the back of their neck but make it obvious so they can feel you smell them.
After like a couple of seconds of LIGHT grinding , I push them out again, and keep theri hands in mine, you can take it from there
Just remember to not be sleazy but keep that eye contact when she is facing u, u want to be polite but also want her to know that u are willing to rip her clothes off and go for it then and there Hope that helps, it works for me
Let me know how it goes