I though of this for an opener:

You walking around, at the parties or anywhere. You see a hot girl walking by and you make an eye contact. Just before she passes ya go like this:

PUA: "I like yer hat/hair/sunglasses/etc." *smile & lean back a bit like your looking at a car if its good looking enough to buy, maybe put your fingers on your chin like business men do*

SHE: "Thanks."

PUA: "I also like your boots" *Keep the posture*

SHE: "Thanks." *Maybe laughing a bit, least is she smiles.* If she doesnt, she isnt a girl you want.

PUA: *Go to normal standing posture* and say "In fact, I like it all."

SHE: "Hahahhaha, thanks"

Part 2, from here it can go different ways

PUA: "Please tell me you can cook?"

1. SHE: "Yea, sure I can!"

PUA: "Wonderful, you like doing dishes and cleaning also, dont you?"

No: PUA: "OKAY, we are so broke up!" *grin*

Yes: PUA: "Ok, we are so getting married! Tell me you are rich, arent ya?!?"

- From here you can carry on anywhere.

2. SHE: "No I cant really.."

PUA: "Whaaat, then you must be rich, arent ya?!"

-She will be laughing. If she isnt, she is boring and you dont want a girl like her.

- From here you can carry on anywhere.

YES SIR,I looove it

And after the break up,you can "give her a second chance..."
Great idea,will test it soon

I don't find it solid.
She can leave after the compliment. she also can say "I've got a bf" before getting to part 2 then what?
And when getting to part 2 she already thinks "he wants me..." that's getting the bitch shield up usually.

Have you field tested it yet?

Well, this is direct approach. The funniness of this opener should knock the thing you call bitch shield down.

She wont be walking by if you have correct bodylanguage, SHOW HER WITH YOUR BODY, that you want her to STOP.

Still, this is better when girl is standing, not walking.

Both parts of this have been field tested, with various success. Part 1 usually made girls giggle and when you give that first impression to someone that you are funny and got confidence to tell someone something like that, she will obviously continue giggling to what you say, even if its not really funny.

EDIT: But I havent tried them both TOGETHER.