So I was at a cafe and sat next a girl HB7 where there was bar style window seating, thinking about making an approach but slowly talking myself out of it. Opened up my laptop to use the internet and realized that the wifi had a password. Not knowing what the password was I used this as an opportunity to ask her if she knew what the password was. She said she didn't but we talked for a minute. Didn't go for a number close and it ended up being just a friendly conversation. Moral of the story is I did my first (official) approach and discovered that asking a girl if she knows the wifi password is a potential opener at a cafe.