Fire extinguishers!! Have a few good extinguishers readily available and know how to use them.
Over the years, I've put out 5 small fires, that easily could have turned into disasters. 2 snowmobiles, 1 jet ski, and 2 motorcycles. The jet ski incident taught me to have multiple extinguishers on hand. I grabbed the 1st extinguisher, pulled the trigger, and nothing

! Grabbed the 2nd one, pulled the trigger, and same thing. Finally, the 3rd, and last one in the shop, worked.
I'm told, that every so often, you're supposed to turn your extinguishers upside down and tap them, to keep the chemical from packing down. A friend of mine was working on a 4-wheeler in his shop. The airbox was full of fuel and when he tried to start it, it backfired and ignited. He pointed the extinguisher at the flaming airbox and pulled the trigger. Apparently, the chemical was packed down at the bottom of the extinguisher, because the only thing that came out was propellant. When the propellant shot out, it blasted the flaming gasoline all over the shop. Luckily no one was hurt but he lost a nice shop and several vehicles in the fire.
From my observation, some/most people panic and aren't of much help. Keep your cool and be the guy that grabs the extinguisher and actually uses it!