Check that the lid is not sealed or damaged
Grip the jar firmly with one hand
Hold the lid with the other hand
Twist the lid counterclockwise
If it is stuck, run the lid under warm water
Dry the jar and lid for a better grip
Use a rubber grip pad or cloth for traction
Tap the lid edge lightly to loosen the seal
Pry under the lid edge carefully if needed
Ask someone else to help if it still will not open