In some areas of the Celtic lands, people believed that a special fire, called the Needfire, could be used to create magical results. However, much like Harry Potter's Room of Requirement, the Needfire could only be created in times of great need. In many areas, Samhain was seen as an opportune time for the Needfire -- after all, the harvest was over, the earth was getting cold, and in just a few short months, your family could be starving and freezing. The Needfire helped to assure that your family would be safe from famine, pestilence, the deadly cold, and other natural disasters. In some nomadic societies, the Needfire was the place to make offerings - if you wanted to have a healthy crop of sheep, for example, you might carve an effigy of a ewe and toss it in the fire. Perhaps you'd throw a few seeds in there to assure an abundant crop in the following season.
Traditionally, the Needfire was lit without the use of iron. It could only be started by rubbing a pair of sticks together, or twisting a rope along a stake until a spark was created. In some areas, it was considered acceptable to use embers from a tree that had been hit by lightning as your starter, but typically, the Needfire was started by hand. Although it can be tricky to start a fire without flint or matches or a lighter -- anyone who's watched survival shows on television knows this -- it is indeed possible to do it. If you practice your technique ahead of time, you should be able to light a Samhain Needfire to help protect and guard your family through the coming year.
There are some excellent resources online for how to make a fire using a bow-drill, which is basically a piece of wood with a string, run along a spindle until a spark is created. Check these websites for an idea of how you can get your Needfire started:
Light your Needfire on the night of Samhain Eve. Once the sparks have caught, and you have a good blaze going, make an offering to the deities of your tradition, thanking them for keeping an eye on you in the coming year. You may also wish to make an offering to your ancestors, invoking them to protect your family.