1) Better to stay away from the dance floor completely and game other girls.
Dance floor girls are distracted by dancing, their friends, and music- go for the girl by herself at the bar.
2) Night club closing at 2am is the golden opportunity for pickup.
Guys don't hit on girls when everyone is leaving.
Most girls wait outside in front looking for someone to talk to-approach now and lead with,
" hey my buddy and I are going to get pizza across the street, wanna join us"?
If you aren't creepy-they'll comply.
Build comfort, flirt, then pull back to final destination.