Do not put 18650 batteries in your pockets and especially avoid contact with other metal objects like keys, paperclips, coins, etc.
Store 18650 batteries in a plastic carrying case when not in use.
Do not store 18650 batteries in a hot environment like your car.
Keep wraps intact.
Use the right batteries.
Watch out for counterfeit batteries
Don’t leave your batteries charging unattended
Use a dedicated charger
Don’t over-drain your batteries
Avoid extreme temperatures
Use married batteries
Replace old batteries
Recycle old batteries