Open:
"Are you in a rush?"
"Do you have a moment?"
"Are you busy?"
Her answer:
Yes = Normal game
Answer is no:
Me: "Okay. Well, my name is Ross, it's nice to meet you.. -pause for name-"
Girl: "Jessica, look I really don't have time for this, but it was nice meeting you too."
Me: "Everyone has time for a 60 second conversation with a man who can change their life"
Set the line, and pulled the hook. Everyone has time for a 60 second conversation with you. It doesn't matter if they are busy or it's just a front. The great thing about this is; if they are truly not interested, they'll walk away, which saves you time. If they are interested, it is glaringly obvious. She just said she was busy and.. oh look, she's hanging around and flirting with you. Clearly you're more important than that other thing.
The idea of not approaching girls while busy is a frightful frame. Who cares if she's busy? I'm an amazing guy, and whatever is going on in her life is nothing compared to what I can give her. Until you can give many girls the time of their life with you and know you're a value providing machine that people love to be around, this frame is hard to achieve. Only through many experiences will you truly have it; but you can certainly mimic it.
I prefer girls who are busy. It shows they do things and go after things, and don't simply sit around waiting for people to talk to them. They are motivated. Plus, in these circumstances, you can easily speed through things as they feel a sense of urgency. They need to go somewhere, but you're there, and it's a hard decision.. So you can easily get a number close in less than a minute with plenty of attraction.
Approach every woman you find attractive. It's been said before; dating is a numbers game. I'd rather fail one hundred 20-second approaches with attractive women (not probable, but possible) and then land a relationship with an amazing, motivated woman on the 101st than to have not tried at all. 33 minutes of failure to get with a hot, motivated women who gives me as much as I give her? Sign me up.