Building a fire with a ferrocerium rod is relatively easy, and can be done with a few basic steps:

  1. Gather materials: You will need a ferrocerium rod, a striker, tinder (such as dry leaves, twigs, or paper), and kindling (smaller sticks and branches).

  2. Prepare the tinder: Pile the tinder in a location where it will be protected from the wind and easily accessible.

  3. Strike the rod: Hold the ferrocerium rod with the striker, and strike the rod with a quick, downward motion to produce sparks. The sparks should land on the tinder, igniting it.

  4. Fan the flames: Use your breath or a piece of cardboard to fan the flames of the tinder, helping them grow.

  5. Add kindling: Once the tinder is burning well, slowly add small sticks and branches to the fire, gradually building it up to the desired size.

  6. Maintain the fire: Keep the fire well-supplied with kindling, and adjust the airflow as needed to ensure that the fire burns brightly and safely.

It's important to remember to always use caution and follow local fire regulations and restrictions when starting a fire.