I do!  I have shop size extinguishers (dry chemical) in the barn and in the garage.  I keep water near by when welding, and the dry chemical is if I have flammable liquids out (thinner, oil, etc.)
I have a metal trash can for oil soaked rags too.
One of the first things I did was replace the rusted out old breaker panel in the barn, and add GFI breakers for the outlets.  Apparently the panel manufacturer went out of business because of fires...
I wish I could put in a deluge system in the barn, but I don't have a water supply that could make it effective, so prevention is the key.
Did I mention that I'm retired Coast Guard?  Semper Paratus!