I have my own personal policy of when to open carry and when not to. Again, this is just my opinion but it follows a very specific principle.
Open carry for me is limited to times when I am in a remote or unpopulated area or where anyone who approaches has to do so from a long enough distance that I can be focused and aware of them. These are times when you might want someone to clearly see that you are armed before they get close enough to have any interaction with you.
Examples of when and where this principle might apply:
Using an ATM outside a bank after hours. These places are notorious for robberies. You would want anyone plotting such to see that you are armed from a long way off so they would pass on you and wait for an easier victim.
Pumping gas late at night. Now that we have the ability to swipe our debit card at the pump there is no reason to go in the store just to buy gas. This would be a good time for anyone who walks up to see your pistol before they decide to get involved with you. If you need to go in the store for some reason, simply pull your shirt tail out or put on a jacket to cover the pistol so as not to alarm the clerk.
Outdoor activities like camping or hiking where you might cross paths with strangers in the middle of nowhere. Ever see the movie Deliverance? "Squeal like a pig boy!" Enough said.
Fixing a flat on the side of the road or other times when you may appear vulnerable. You would want anyone with nefarious intentions to see that you are armed from the road and just keep going.
Walking to or from your car in an empty parking lot. For example, my warehouse is in a deteriorating part of town. I want any crack head who is contemplating using me for an ATM to get the message “Don’t tread on me” from afar and avoid any contact whatsoever.
I could go on and on with examples but the overriding point is that in all of these scenarios I would be alone or vulnerable and anyone who approached would have to do so from a distance thus giving me plenty of reaction time. Under those conditions they would have my full attention long before they got close enough to become a threat or worse yet, snatch my weapon.
The times I would choose NOT to open carry would be anytime that I have to let strangers get within my reaction zone. This rules out any crowded public place. I know my limitations and I am just not that fast out of the holster therefore, my reaction circle is pretty big, at least ten yards in every direction. I don’t want people who get that close to know I am carrying because it shifts the element of surprise from me to them.
This is why uniformed guards in schools are such a bad idea. If a determined murdered knows who is armed he will simply take them out first. Or exponentially worse, use the guard for a gun store by luring him outside under false pretenses and knocking him over the head while he is distracted by some fictitious problem. When the bad guys don’t know who is armed it makes everyone safer.
If for whatever reason I did have to open carry a within snatching distance of the public, I would defiantly not wear the pistol behind the hip where It can be taken by someone who manages to get into my blind spot. I would choose a police style retention holster and wear it in either the appendix carry position or the 10:00 cross draw position so I can cover and protect it with my hand. I also would choose a pistol with a positive safety such as a 1911 just in case someone did manage to grab it. After handing a locked and cocked 1911 to enough Glock shooters at the range, only to have to show them how to take the safety off, I am convinced that the typical criminal who is not a recreational shooter would never figure out how to get the safety off before I punched his lights out.
Open carry to me is sort of like wearing a bathing suit in public. There definitely are proper times and places for both but they are limited by practicality and decorum. That being said, the last thing I would want is the government making that decision for me.
Again, this is just my opinion.