Lithium Batteries:
Know what kind you have LiPoly, LiIon, etc. Have the proper battery charger for that particular lithium battery family.
Get a ceramic bread pan and put the battery in it while charging.
Dispose of batteries that start to bloat.
Having the proper battery charger is not a panacea, my boss nearly burnt his garage down with a LiPoly on the approved charger with cell balancer, the breadpan would have prevented a lot of damage and reduced it to mostly smoke damage.
One of the local RC guys burned his van to the ground, the Li-Ion battery was left on the seat, caught the seat on fire and then the rest of the contents, balsa and monokote burn nicely, add a gallon or two of alcohol fuel and the rest is history. Not sure if he was using the proper charger or not.