With more and more women speaking openly about street harassment, a straight man can get a little confused about approaching a lady in public. or is wearing the t-shirt of your favorite obscure '80s hardcore band. If the answer is yes, then maybe you should let it go; she probably doesn't want to be bothered and you have to respect that.
"You mean a woman doesn't like it when I pull off her headphones on the subway? You want to say hello, understandably, but first, please take notice of whether or not she wants to say hello to you or anyone else for that matter. Remember, no one other than your therapist or attorney owes you a conversation — so be fucking cool already.
In the interest of human connection, here's a handy guide on how to approach a woman in various situations.
But let's say that you're just a chill dude who still can't quite grasp the best way to approach an unfamiliar woman in a public space. Dating and flirting is, in general, an awkward thing to do and that goes double for when you're going up and introducing yourself to someone out of nowhere. It possible to approach a lady in a respectful and flattering way that probably won't leave her feeling offended or worried that you might be a subway masturbator.
You may think it impossible to make that call, but women are human beings and, just like other human beings, they show signs of wanting to be left alone. What if she's not power-walking in the opposite direction or actively avoiding looking at anyone on the street?
Then it might be okay to approach (remember, different people react to things differently).
The most important thing, as is the case when talking to anyone, is to treat her like a (\ˈpər-sən\).
Don't make kissy noises at her like she's a dog (we women tend to really hate this), don't imitate the sound you think her butt makes when she walks (a "hello" is much more effective than "badoombadoombadoom") and don't tell her that she'd be prettier if she smiled. If so, she's a lady with an agenda and, by interrupting her, you risk being a jerk.