How to get to know a girl

[InvaderNat]

So heres the deal. The other day I met a really pretty and nice girl at a one-off job where we worked together for the day. I talked to her for a while and got to know her and some of her interests a bit, one of which is social field hockey which I also play (at the same place and time).
Problem is when I went up to her after the game I didn't really know what to say to her apart from asking her about her game - she smiled and responded politely but that was about all I could say to her before I moved on.

What I need advice on is how to talk to a girl I've only met twice and keep the conversation going. Also I've only got two more opportunities to do this before the general rounds of the social hockey games end; I'm not sure if we'll make it into the finals.
I always struggle to find things to talk about with people I don't know very well, and to come up with opening lines to say to them.

What things do you guys think would be good to say to her? I'd really appreciate any suggestions.

p.s. Just a bit background information - she's 19, I'm 21, we're both quite good looking (or at least I've been told I am by girls before), we both live in the same city and she's at university studying environmental planning.

[Axiom]

Well you don't need any "opening lines" because you've already met. You've gotten to the point where it's fine to just walk up to her and enter a normal conversation from the get go. I can't give you entire scripts of what to say during the conversation, you're gonna have to figure it out beforehand and/or improvise, but off the top of my head here are a few general ideas you should keep in mind.

1. Don't show too much interest. You don't want her to feel like she already has you before she feels like she's earned your interest and attention. Be a bit of a challenge, and make her work a little to win you over. Basically, you want to give the impression that you are interested, but you're indifferent to the outcome. You want her, but you don't need her. Do not look desperate. The desperate guy changes who he is for a girl, does everything just in the hopes that she will like him and spend time with him; he doesn't have boundaries or standards. A confident man doesn't need that from a woman.

2. It's not just what you talk about, but also how you talk about it. You want to avoid being overly logical. For example, if you were talking about field hockey, don't just talk about statistics. While it may be interesting from an athlete's point of view, there's nothing emotionally stimulating about that conversation. You want to be able to make a girl feel good when she's with you. So avoid the stats and talk about things like why she likes playing field hockey, what she's passionate about, etc. So there's field hockey, and you know what she's studying, so you could start with that and take the conversation from there.

3. Humor. Make her laugh. I don't think this one really needs any explaining. Just don't fall into the trap of making nothing but jokes, or you'll go from being an interesting guy with a sense of humor to her pet comedian.

4. Compliments. Be careful with compliments. Never compliment a girl on her looks, at least not until further down the road. She's probably had literally hundreds of guys come up to her and tell her how beautiful, hot and sexy she is. Hitting her with a comment like that just lumps you into the category of guys who were only interested in her looks, and that doesn't say anything good about you. If you're going to compliment her, make it something about who she is, and not how she looks.

This ties in to number 2. Say she just told you a story about why she's studying environmental planning, you can tell her, "You seem really passionate about XYZ, that's really cool." And there ya go. Basic idea is that your compliments shouldn't be free, and they shouldn't be something you say just to get her to like you more. They should be genuine. Look for things to compliment her on after you've been talking for a little while.

5. Think of a story you could tell her. It's a conversation piece, and if you go blank during the conversation you can throw it out there. Something funny, interesting, something that says good things about you (but don't brag. It can't be try-hard). It will add to the conversation you're having, and give her chances to comment on it, and then you can take her comments and steer the conversation in other directions. Don't take it so seriously. Have fun with it.

6. Be bold. If she's into you, she will be dropping hints. Things like laughing at your jokes (even if they're not that funny), touching you, playing with her hair, facing you with her body (as opposed to turned away and generally looking bored or disinterested) asking you questions, contributing to the conversation and picking it up if it dies down, etc. Once you notice that she's showing you some signs, don't be afraid to make a move. Get her phone number, hell, set up the date right then and there if it's going really well. Don't be afraid of rejection.