First rule of gun ownership. Never point a gun at something you dont want destroyed. Second rule of gun ownership. Keep finger off of the trigger until ready to fire.
The NRA lists the 2 primary rules of gun safety as follows.
1. ALWAYS keep the gun pointed in a safe direction.
This is the primary rule of gun safety. A safe direction means that the gun is pointed so that even if it were to go off it would not cause injury or damage. The key to this rule is to control where the muzzle or front end of the barrel is pointed at all times. Common sense dictates the safest direction, depending on different circumstances.
2. ALWAYS keep your finger off the trigger until ready to shoot.
When holding a gun, rest your finger on the trigger guard or along the side of the gun. Until you are actually ready to fire, do not touch the trigger.
I like to use the following:
Always treat every gun as if it were loaded and never point a gun at anything you do not intend to shoot (destroy just sounds dumb IMO-guns don't "destroy" things, they discharge bullets which tend to just put holes in things). Followed by, always keep your finger off the trigger until you are ready to shoot.