So I got a girl's number (from a dating site).. and we sent each other a bunch of texts. I was being cocky-funny and teasing her, things were going well, I was getting responses like "Lol! Shutup!!!", etc.

Then I called her, and she told me, "haha you act all badass when you're texting me but then you call me and get all shy!"

Errm...

Fuck.

Back to the drawing board. How can I learn to conversate freely and smoothly? This sort of thing happens quite often. When I'm talking to a girl on the phone, I can't seem to think of what to say, and my vocabulary becomes reduced to "Hi", "How do you do", "Yes", "No", "Cool", "Okay", "Talk to you later", "Bye". I can think of lots of funny/interesting things to say beforehand, but when I'm in a real conversation, they just don't seem to make sense, or they don't feel contextually applicable, or I hesitate too much.

I've tried calling sex lines as practice, but they're very artificial, because the girls on sex lines will talk about anything without any restraint, and will actively try to engage you in conversation themselves, because they get paid by the minute while you're on the line. Which therefore wrecks the purpose of the exercise, since I know the conversation will stay lively no matter what I say (or don't say for that matter). (Not to mention that they keep trying to talk about sex, even if you tell them you don't want to!)

Any tips?