What i found out, what works pretty well for me at a club:

Open many sets and ask them where they are from. You don't even have to get there names or something, but do remember where they are from. Then leave the set after about 1 Minute talk and say you have to grab a new drink or something.

Then approch the same set after about 20-30 minutes and say something like:

"HEEEY, my friends from [spain/germany/miami/whatever]". Hug them or give them hi five. They will recognise you from earlier and they will trust you as seeing you as a friend now. From that on you can continue to game.

I said something like: "Want to go to the chillout-area, grab a drink there? Its quiter there". Last time a got a girl following me there and we were kissing.

Good thing about that routine is, that its quite easy to do and girls love to see a "friend" come by, they new from earlier in the evening.