It doesn't really matter what you say as long as it captures their attention and is positive.
an opener which works really well and i have field tested numerous time is this one;
(Best for daygame, but also really good for nightgame) Look at the girl you want to open make eye contact, look surprised and say 'HEEEY! LONG TIME NO SEEN!

' and walk up to her give her a hug. She will most likely respond with 'heeeeey! yeaahhh,, long time no seen!'.
Just act like you know her from a while back, when she says she doesnt remember you, you can act offended that she forgot about you or tell her you were just joking and just wanted to talk to her
This is a VERY positive, funny, relieving, original opener which instantly makes her emotions go crazy.
You can keep the jig up as long as seems appropriate, I usually let it last untill she gets into panic mode haha.
Try to avoid bitches with this opener

Read their body language
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The hardest part of gaming is knowing when to release (hook - pull - release). If you time it right she will cling to you, because she enjoyed you and wants more

And she will be more than happy to #close