Dude, good job, at least the next time wont be as awkward because you have some sort or rapport, but I think youre focusing too hard on one girl. You are planning an entire interaction with her a week or 2 before the interaction? Its hard to come across genuine and casual when you arent.

My advice is to practice and apply general PUA techniques in your every day interactions. Social calibration is the vehicle in which you can confidently talk to anyone.

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Its not the material-----Its the Execution

Why not open some other random people sitting around you, and make them laugh? You will be the center of attention, and the cute gothette will notice. This also makes it less like you're chasing just her, and more like you're generally a fun, talkative guy. Once everyone's laughing, use an opinion opener on her, and when the lecture starts, do the thing with the notepad. By the way, it will probably score points that you know of Siouxsie Sioux. Why don't you ask if that's where she got the inspiration for her hair, then neg her about it, then joke around a bit.