well depending on the class..there are different topics. like art class? give her some praise for her work, or maybe even throw out a suggestion, or ask what you can improve on your piece. the third one is pretty good, that means you appreciate her opinion. that would open up some communication, more than likely she'll feel like she can ask you about what you think about the piece, and you can tell her what you think and also start up a convo.
if it's a class setting? sit near her, either next to, infront or behind her. if somethin is confusing, don't be afraid to lean over and ask her what the professor said. again, asking for help, letting them know that they are needed.
if you can make her laugh, do it. even if a slight at your expense...like "woah i'm out of it my brain is dead" or something like that. if you make her smile? defenses start to lower and then you can introduce yourself.
and here's the thing, the cuter the girl, the more likely she's lonely. the really beautiful ones are more than likely seen as they're out of our league, or they must be taken. which believe me, unless she's a stuck up bitch, she's not out of your league. and she's probably wanting to talk to you anyway!
also read her body language. if you see her feet or her arms, fingers pointing at your direction, then that means she's subconsciously pointing you out and into you. she could be talkin to her friends but if she's pointing at you, then she notices you. and if she's pointing at you and her legs aren't crossed or slightly open?...TALK TO HER RIGHT AWAY lol, that means she pretty much finds you sexy and is literally opening her body up to. does she push her hair aside showing her neck? she's showing you a very sensual spot and is trying to attract your attention to it. a good thing.
if she crosses her legs so her calfs are parallel to eachother, then she's showing off her leg muscle, which gives the legs a more youthful appearance...again another sign.
if she looks at you and plays with her pen..she's playing with a phallic object. if she wears sandals or whatever and keeps sliding them on and off...that's another subconscious motion of the act of sex itself. if you see her doing ANYTHING in and out with her hands or feet..especially in rhytHydromax, then she's noticing you in a big way.
that's just a few things, and no i'm not makin this shit up, i have read it in body language books and everything else..and it's proven to me to be very very affective.
ohhh yeah..also if she plays with her lips..licking or tracking them with her fingers, then that's a good goooood thing, because the lips on a woman is developed to be a mirror image of their vagina. a nice full pair of lips upstairs, means that she probably has nice full lips downstairs. same thing with thin lips.
...idk that's all i can think of right now lol..good luck and hope it helps
so first off i always had issues with meeting new girls and what to say. but their is this one girl in my class who i think is very cute and i always wanted to talk to her but dont got the balls. i was thinking about talking to her after class and all but dont know what to say. can u guys give me some advice on what to say. like i know introduce myself and stuff but then what? what should i say. info appreciated from the experts 
