1. Watch the muzzle!
Keep the firearm pointed in a safe direction at all times.
2. Treat every firearm as a loaded gun.
Loaded or not, always treat a firearm if it were loaded.
3. Know your target, what is in front of it and beyond it.
Know what you will be shooting at, any obstacles in front or near it, and what is behind it.
4. Keep your finger outside the trigger guard until ready to shoot.
Never place your finger inside the trigger guard unless you are willing to destroy what is in front of you.