Always use eye protection when working with  compressed gases

Build rockets out of lightweight plastics, never use metal or breakable materials such as glass

Never pressurize a rocket to a greater pressure than it has been tested (test with rocket completely full of water)

Never pressurize a damaged rocket, it may fail at a lower pressure than expected

Always pressurize a rocket from a safe distance

Keep people at least 50 feet away from a pressurized rocket

Never hold a pressurized rocket

Never aim a rocket toward anyone

Ensure that everyone around is alert and aware of the potential danger of a pressurized rocket

Ensure spectators are alert and aware of the dangers of a falling rocket (particularly in event of parachute/recovery system failure)

Never launch a rocket anywhere near buildings, cars or property that could be damaged

Always launch rockets straight up, never at an angle nor horizontally

Never put any human body parts above a pressurized rocket - a misfire at the wrong time can knock your block off.  A rocket hitting your face, or otherwise can cause serious injury including loss of eye-sight.  

Never launch near power lines

Never retrieve a rocket stuck in power lines - notify power company in this case

Keep hands away from rocket nozzles during launch - never launch by hand.  The force of water coming out is powerful enough to break bones.

Use only compressed air and water. 

During rocket construction, work with adhesives only in a well ventilated area.  Use of a respirator is recommended.

Make sure to follow all relevant local, state and federal regulations