A rule of thumb I picked up someplace (might have been one of Gavin de Becker's books, but I'm not sure) is to be especially careful and aware when you're in a place where it would take you more than 30 seconds to reach a place where there is a crowd, or where it would take help more than 30 seconds to reach you.
Parking in a well-lit area is a good thing if you can, especially at night, but I'd rather park close to other people and carry my Surefire flashlight in my hand than park farther away to be near light.
One other suggestion: It turns out that dropping what we're carrying in order to face a threat can be challenging because of our conditioning. I've actually practiced this - I'll hold a book, grocery bags, purse, coffee cup, etc. in my hand and, on a cue from a friend, I'll see how quickly I can drop what I'm holding and come into a "ready" stance.
Tammy (in Santa Barbara County)
"Courage is the price that life exacts for granting peace." ~ Amelia Earhart
"Experience is what allows you to recognize a mistake the second time you make it." ~ Unknown