There is a stupid simple answer to this.
be aware.
At every second that you are out, be mindful that you are carrying a loaded gun, and that at any second you may have to use it. Don't park your hind end on a park bench with your back to the rest of the place and wrap your brain around your phone while your gun is stuffed into a waist band holster under your jacket.
Be totally, absolutely prepared to drop that case of wine, plonk it straight to the ground and survive the attack. If you are driving with a pistol, how in hell are you going to draw that IWB holstered 1911? Be honest with yourself, if someone smashes your window in with a bat while you sit at the curb texting, is he going to drag you out and beat you without having a chance to wriggle your weapon free?
In the real world, the Sensei doesn't say "go". There is no bell, starting pistol, dude at the front of the class who says "Okay, pick up your pens and start the test."
You, and only you, are responsible for saving your own life, and if you want to do that, you have to put the effort into learning how to do it. Get into the scenario, understand the process and how you will have to solve it. Going out and shooting cans isn't going to work, you have to practice the discipline of war. Learn the enemy, understand his capabilities and common practices, learn or create intelligent plans to deal with as many concerns as you can think of. When you are out and about, or elsewhere at potential need of drawing the gun, use that as a teachable moment. Go to a restaurant? don't be stuck at a booth back by the potty closet, request an table that faces the door, away from the cash register.
Many people think that getting the thing and learning how to poke holes in cardboard makes them safe, even more people think that a box of ammo when purchased is enough to make them bullet proof. Oh, how naive. My dad bought his first and only pistol after being attacked by a grizzly while fishing. He bought a box of ammo with it, fired that box and replaced it. Yep, seriously, he ran one box through it in the thirty years that he owned it, and NEVER too it out of his drawer.
Training without real world encumbrances is ineffective. Imagine that somebody has released his pit bull on you when you stumbled onto a robbery or other event. Your pistol is buried under a zipped leather jacket, you have a hot pastrami on rye in one hand and a big gulp in the other, and absolutely no hope of getting a shot off before bowser is gnawing on your knee cap. No, you can't just toss the sandwich and shout "get the stick, boy! Get the stick!" Whenever you are conscious, you must be aware of your circumstances and how your handgun is situated in regard to whatever may happen.
We have had numerous discussions about shooting to wound by shooting at the hip, and many, many people believe the old nonsense that shooting at the femur joint is safer than taking a chest shot. Lord knows, they guy may be wearing a vest, or have a Gideon's bible in his shirt pocket. I am guessing that not a single one of those people who believe in femur shots has ever spent an hour watching passers by and trying to correctly identify that target zone in the same amount of time as it would take to find the middle of an assailant's chest.
It's every person's responsibility to pull his own steak out of the campfire when the wind blows the tent over. Don't wait for the guy who is teaching you how to handle a gun and develop your accuracy to spend hours teaching you that you shouldn't bind your hands while walking or turn your back to the bunch of hoodlums in gang shirts when you walk past with a gold watch. It's not his job, and admit it, nobody is going to pay $50 an hour to hear "it's okay to drop that bag of groceries if someone tries to steal your wallet."