The Witch's Broom or Besom

The Witch's Broom was believed to have many magickal properties, not least of which was being able to fly through the skies and take the Witch on a magickal journey. Owning a broom was a clear and evident sign of Witchcraft then, and a Witch would use the broom in a variety of ways. But how did this innocent household object become so iconic of the craft of the Witch? What customs surround the broom, or besom? And how can you use a broom in your magickal practice?