Don't mistake IOI's from just plain nerves. If she's a beta, she could be very nervous in a lot of situations and do things that make you think she's sending you IOIs up the wazoo. (psst, btw: it's good that your inner game assumes they're IOI's. Always assume attraction. You're not giving yourself enough credit, Fogell. You've already got the mindset to become a great PUA in you. You just have to learn to notice it yourself

)
As for next time, I'm going to give you some lines, but I don't want you to rely on them for the conversation to work. You'll learn nothing that way. I'm giving them to you as a slight push to get you rolling.
"Sup, girl? (AND SAY IT EXACTLY LIKE THAT!!!) I've gotta get these to *location*.
(In a joking tone) Just don't ask what's in it, for your own safety.
(once she asks what's in it) Wow, you have no survival instincts."
(regardless of what she says) "Nah, it's cool man (btw, I've found that calling a girl "man" is a great disqualifyer), but you definately have lost some points in my book".
Just let the firting flow. You'll get it. I trust you.
-June