How do you prevent arcing in electrical contacts?

Arcing is caused by current trying to sustain its flow by using the air as a conduit. If the travel is very far the arc will dissipate as lack of paths. If the current is great it may sustain itself. All contactor have a biult in shoot trough to channel the energy harmlessly, A capacitor across the contacts can help by absorbing the difference in voltage when the contacts disconnect or connects