Never used "pick up" lines.
A couple I've heard;
"Girl, you must be exhausted, because you've been running through my mind all day".
"You must be wearing mirror pants, because I can totally see myself in them".
In HS, a workout buddy and I would "holla" at girls as they walked by. Not being serious, of course, just to be "goofy". We'd say stuff like "hey, have you seen my new hair cut?" *pointing at hair, bisep flex*. "Check out my new shoes" *pointing at shoes, tricep flex*. As offensive as it is, we'd get the most giggles from "Do you have any Irish in you?", followed by "you want some?". Horrible.
I can't recall a girl having attempted a "pick up" line. First gf in HS just came over to me in class, grabbed my butt, and introduced herself. Most common in passing was a simple "I don't normally do this, but..." and offer their number.