Pickup lines don't work.. period, end of story. Yeah you might learn something smooth to say that's funny and will get a woman's attention, but why? Why do what every other guy in a club, bar, or on the street does in order to get the attention of women?
Pick-up lines are for losers. You shouldn't have to memorize a bunch of lines that other men have made up in order to seduce women at clubs or wherever. It's truly amazing how many men think that memorizing a bunch of lines will get them a date.
Look, hot women get hit on constantly. Chances are that the woman has heard whatever line you're using on her. If she hasn't it will be similar enough that she'll know what it is, a line. When you do what every other loser does, then which category will she place you in? Yeah that's right, the one that starts with a giant L.
If you absolutely must use a pickup line, then simply walk up to a woman and say "Hi, my names 'whatever,' what's yours?" That's an acceptable pick-up line. And then start up a normal conversation. The conversation can be about anything. Ask her about what she's doing, what she's wearing, her advice on something. Just open your mouth and be genuine.
Women don't want to hear regurgitated garbage. It's not the lines you use or even the words you speak that are important, it's how you present yourself. It's showing her confidence and a sense of humor. If you can make her laugh you're golden.
Learn to approach women and say the first thing that pops into your head. It's no big deal. After a few minutes of conversation say that you've enjoyed chatting with her and would like to do it again sometime. Then you'll either get a phone number or you won't. With practice your confidence will grow and your ability to converse with complete strangers will improve.