After number closing. You should still chat for at least couple more minutes. Unless is she or you have to really leave.
When she leaves, 10 minutes later, text her saying "Hey, nice to meet you" And she will reply back "you too" and just leave it at that.
Text her the next day. But do not text her to ask her out or to see what your up to. My goal when I am texting is self amusement. I usually text something random like "I would so beat you in monopoly." She replies and start having fun from here. There is really no lines from here, your gonna have to make stuff up. Key thing to keep in mind is have fun! Don't be needy.
What usually happens, maybe not the same day but couple times around is girls hint for me to ask them out. I usually ignore it the first time, but the 2nd time, I set something up.
check this thread out also for some fun texting.
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