I know that just being yourself can be really difficult, especially since we usually don't think that we're good enough as it is, but it's important not to try to be something that you're not 'cause most girls see right through that. But go talk to her, pay her lots of compliments, listen to what she says and let her know that you value her opinion - just be nice to her. Oh, and when you get to know her better, don't forget to buy her flowers on occasion, girls love that 'cause it makes us feel like you're making an effort to put a smile on our faces

And I know this probably isn't much of a comfort to you now, but it will get easier with practice - just look at all the pretty good advice you got in this thread (well, some of the remarks were more useful than others, I guess...
