I think a combination of keeping up to date using what Rusirius talked about, but every x amount of years, taking a hands on course would be a nice mix.
I put as much faith in watching people, your surroundings, then the accual using of the last option. Just sitting for 5-10 seconds in your car when you park, looking around, ect. Scanning parking lots for 3 seconds before leaving bank doors. Accually stoping to talk to your next door neihbor once in a while, stuff like that.
Trying to avoid, through awareness, is half the battle. Sometimes you cant control that other half, that is what advance classes are for.
Condition, they used to have a place in Pa? But stoped a few years back? I think due to worry about who, was taking classes. Advance AK, or AR classes, i believe. If I find the link, I"ll pm you.