I am a college student (m21) and I have a hour break in between classes in which I go to the local Starbucks to practice approaching women. However, I have not had any success. I sat in the 'bucks 3 times last week and I haven't been able to make a single approach. When I go out at night I don't have any trouble approaching people, even when completely sober, but when a girl is sitting at a table reading a book or studying for a test, I find it hard for me to approach. Does anyone have any advice on doing cold approaches during the day?

tldr: I need help with approaching girls in a starbucks while they are preoccupied with other things.