This one is great:

Go find the Dating for Dummies book. It's bright yellow and black. I forget the exact page (78 maybe?), but find the page that has "NEVER USE THESE LINES" on it, and keep the book open to that page.

Walk up to a girl BLATANTLY and hold the book up in front of your face so she can easily read the title. She might start laughing, depending on how you do it.

Then slowly lower the book and read the lines. "So... come here often" in a super player voice. She will crack up and answer you. Break your "smooth" look on your face and quickly bring the book back up and read the next line "What's your sign?". She will laugh again and probably answer.

Then I usually say "Wow... this works great. Your turn". It puts her on the spot. You can flip to random pages and do tons of role-play... the breaking up stuff is great.

Eventually just stack with a relationship related opener, and you're in. I've done this a ton of times and it never fails to open.