Treat EVERY weapon as if it were loaded, even after you've ensured it to be unloaded.
Keep YOUR finger straight and off the trigger, outside the trigger guard until your sights are up on target and you are ready to shoot.
Never cover ANYTHING with the muzzle of your weapon you are not willing to destroy.
Be SURE of your target, consider the foreground and background.
"Responsible firearms ownership is much more than simply owning a gun and ensuring it's locked up. It's a continuous process of training both the mental and physical aspect. Marksmanship is a highly perishable skillset, but to a higher degree, the mental training must encompass that the intent of the weapon, is to take a life." - Director of Security