Jeff Cooper's 4 basic rules of gun safety just seem wiser the more I know:

1 All guns are always loaded. Even if they are not, treat them as
if they are.
2 Never let the muzzle cover anything you are not willing to
destroy. (For those who insist that this particular gun is
unloaded, see Rule 1.)
3 Keep your finger off the trigger till your sights are on the
target. This is the Golden Rule. Its violation is directly
responsible for about 60 percent of inadvertent discharges.
4 Identify your target, and what is behind it. Never shoot at
anything that you have not positively identified.

qjs