Recently a comment was posted that I couldn't agree with more "The way you carry yourself and not the fact you carry a weapon is what will make a bad guy pause". Here is a comment from Col. Grossman on that very topic and although he uses the term which I personally can't stand, sheepdog, it fits perfectly.
There was research conducted a few years ago with individuals convicted of violent crimes. These cons were in prison for serious, predatory acts of violence: assaults, murders and killing law enforcement officers. The vast majority said that they specifically targeted victims by body language: slumped walk, passive behavior and lack of awareness. They chose their victims like big cats do in Africa..., when they select one out of the herd that is least able to protect itself.
However, when there were cues given by potential victims that indicated they would not go easily, the cons said that they would walk away. If the cons sensed that the target was a "counter-predator," that is, a sheepdog, they would leave him alone unless there was no other choice but to engage.
Lt. Col. Dave Grossman, On Combat
If you look like a victim you will be treated as such. One of the reasons NYPD's decoy unit is so successful is that they have the look of an easy victim down pat. The bad guy just like was stated about the big cats cannot resist an easy meal.
No matter how you carry be aware of your surroundings, make eye contact with people, think about what is going on around you, if it does not look or feel right it probably isn't. In a parking lot take a moment to scan the areas around you before you get out of the car. Take a second look as you get out and stand up and take a final look as you reach the rear, or front depending on direction of travel, and leave the safety of your vehicle.
A person intent on causing you harm will notice these actions and may decide to wait for someone else to come along.