You're pumping gas late night. Someone approaches. You prefer to keep them at least 20 feet away from you. What's your strategy? Even if they don't threaten you, can you draw if they cross into close distance?
Every situation is different and I like to stick with teaching mindset but in this specific scenario I might pull the gas handle out visibly and start a polite but loud conversation asking them what's up. No one wants to catch a face full of gas ;) If someone is gearing up to do something to you, you want to do things that will disrupt their decision making. Throw some curve balls at them.
Not sure if this is the kind of question you're looking for, but here goes. If I'm walking from point A to point B in the dark, in a place like a parking lot, what's the best way to ensure that I don't get snuck up on? Specifically, is there anything beyond just constantly looking around (or is that even a good thing to do)?
Looking around is a great way to know what's going on around you! It's simple but critical. On the other side of the coin you look like a "hard target" to any possible criminals. Parking lots are the worst because everyone is head down in their phones and they have no clue what's going on around them. A simple step like keeping your head up and having general awareness is a big step. As a final note, trust your gut. Your brain processes threat way quicker than you can keep up with so if you are getting a fear response, pay attention.