There was a girl sitting outside with headphones on, studying the other day. I sat down near her and started reading a book. I looked over at her, she saw me looking, so I just pointed to her book and asked, "What do you got there?" and we were talking. We talked for a good 10-15 minutes. I wasn't feeling the number close vibe so I told her I had to go (which I did) and left her my card, really expecting nothing. I got an email the next day:

"I was pretty impressed by your gesture yesterday, considering I had my headphones on and such. It takes a certain level of maturity and confidence to just start talking to a complete stranger."

She added that she wasn't looking to get involved with anyone, which of course is usually a fiction, "However, I really enjoyed the ego boost."

TL;DR Just approaching in a difficult situation can be a DHV. You can make a girl's day just by approaching.