Where and when to meet women
The woman at the ATM machine might be fantasizing about having wild sex with a stranger. The point is not necessarily to rule out an approach, it's to look for the easier, more natural approach. Again, we are looking to increase the odds of success.
Is she sitting, standing, walking, doing cartwheels, running away from you, running towards you?
It's pretty tough to approach a jogger, even if you're jogging too. It's pretty easy to go talk to a woman that's slowly walking down the aisle at a bookstore browsing.
There's a different dynamic depending on what she's doing. If she's at the ATM machine, let her finish up and walk away before introducing yourself. If she's sitting on the train with nothing to do, don't wait till she gets up and leaves to come up with the perfect opening line. How long is she likely to stay where she is? How long have you got? Be sensitive to the situation. Be aware.
What time of day is it, and will she be comfortable talking to a stranger?
If it’s late at night and she's walking down an unlit street, that is not a good time to approach, unless you like the taste of hot pepper spray. If it's late at night and she's sitting by herself at a bar, that's a different story.
Daytime on the same street might be fine. Once again, it's about being aware of what's going on around you, and thinking it through. Don't get bogged down in this, just make a quick assessment of the vibe. If you think the woman would feel threatened or scared if you approach, don't. Otherwise, go ahead and see how it goes.
Group dynamics and Set Theory
Is she alone or with friends?
You might think that if she is with friends it's a bad time to approach. Actually, this might be a more comfortable situation from her perspective than if she's alone. She has her friends around her, so she doesn't have to worry about strangers approaching. If you can charm them all and join the group, great. If she sees that you get along with her friends, she's more likely to warm up to you as well.
Negging and "Cocky and Funny"
There are some who advise virtually ignoring the woman you want to meet while chatting up her friends.
You then refer to her with teasing comments, like, "why do you bring her along, she's a handful." In the pickup artist community this is called "negging," and means making joking negative comments. This actually can be very effective, but I'm going to suggest you not do it. A more straightforward approach can be just as effective, and will probably feel better. Anytime you feel you are being manipulative, you're likely to have second thoughts about what you're doing.