Ok Alex so bear with me on this and try to keep the dynamic of interaction in your head when you are reading this. Verbalizing things without showing you interaction is really hard to do for it to make sense.
(and believe me if I don't word this correctly I will be under fire from my female peers on the site here ).
The art of pick up is a seriously complex situation and requires tons practice and tons of failure to actually learn to "read" the dynamic, which should be thought of as training. Now the actual situation and its dynamics is really tough to explain verbally without SHOWING you but just follow me on this one. So when approaching a woman to talk to her you should not really give it the tone of "i want to pick you up" or "i want you" it literally should be something light and polite, witty in a sense, but also confident without being cocky(in most cases). In all honesty you should not care if she doesn't have any interest, but you still want to put in effort to see whats behind the first "layer". There is a dynamic of interest and physical attraction, honest communication and expressing your interest without being "cheesy"(unless doing it sarcastically, if you read her as someone who would respond), but also without being clingy. In other words, you should kinda show her you are interested in her, but really inside you should be a situation of really not caring..because in all honesty if you are looking to pick up it is going to be a game of numbers..ie. not everyone will respond and your "game" isn't going to work with all women. Keep it "light" is the name of the game.
The "game" everyone talks about is getting someone interested in you and there are a million variables to this. Some ladies like a challenge if a guy is maybe a "little" interested but not SUPER interested. Some women like a persistent guy, but not in a stalkerish way, more of a way like you just take her hand and pull her to the dance floor to dance if you are in a club. If she is being shy or acting like she doesn't want to, you can literally put it on her and ask her "why are you being so weird, its just a dance" put the "pressure" on her so that SHE feels weird for acting weird and she may respond by dancing which would be part of your middle game transition. The middle game part is basically getting her interested enough that either you "pull" or you finish it out by getting a number, a kiss, or whatever the case. At this point and again WITHOUT TRYING, you want to be having a good time enough time that she is too..again by keeping the situation light. YOu should note this is different that the somewhat aggressive physical game transition that some like to play - again it works in certain situations and is actually pretty successful even for less than handsome guys if they can practice enough. At that point it becomes less about the aesthetics of a person, though it definitely helps to be decent looking. Again though this is part of the read on each girl to what you FEEL she is going to respond best to.
There are girls that require more physical interaction, more overall stimulation to maintain interest, some are less work - every single one is different and thats where the practice and "read" comes into play over time.
In my travels, I have never met a woman that likes a clingy dude. They want to feel like they are worth "working" for. Even girls who I have approached that at very first word said they weren't interested ended up being very interested after some good effort. Some even werent interested because they had boyfriends but for the simple task of "practice" I would play the game. In fact, actually thinking about it, as long as I showed a girl I noticed her, I had more positive response by paying LESS attention to her than the other way around. But again, thats just how my "game" developed. Not everyone likes this or wants it this way - so keep this in mind as everyone is different.
So the easiest, best. high percentage opener is literally "Hi, my name is Alex" and put out your hand to shake it. Most will respond by saying their name, and shaking your hand. From this point on, the situation needs to stay "light" "careless" and "enjoyable" if she feels like a piece of meat, she will walk and you will need to keep "playing". So at this point you have a bunch of options but the idea is to keep her smiling, keeping the situation fun because once it becomes too serious, many girls fall off.
So really the best way to "practice" is just to talk to people, not even at the clubs. Supermarkets, stores, sidewalk conversation. A good goal is too try to get a woman smiling once a day. This doesn't need to be a compliment or something even remotely serious, just get a smile. An old saying USED TO GO "if you can get a woman to laugh you can get her to do anything" now this isn't necesarily true, but getting a woman to smile and laugh and creating a light, enjoyable conversation or situation going is a sure start.
I do this conversation/laugh/smile thing on a daily basis no matter where I am, and really I don't care what the outcome is because unless I wanted to persue a woman I probably would never see them again based purely on numbers. As long as I get a name and a smile and laugh thats success and the "in" to move along with whatever else I wanted to try. The other reason I do it is because its DARN enjoyable to make people laugh and smile plus it keeps me sharp on just dynamic conversations in general.
So in short there isn't a specific pickup line that is going to work, the easiest "in" is your name and your hand. From there you just have to keep the situation light(I don't like buying drinks by the way, I instead tell them(carefully) to buy me one) and as long as you practice practice practice practice, you will be able to convert your openers to having a fun middle game and eventually either pulling a girl or closing it in whatever way you want at the time.
You gotta get out there though and practice TOMORROW - if you want to be good at game, you have to practice and not give a care to the response if its less than what you wanted.
Got it? :)