Incense has long had associations with magick and witchcraft, as indeed it is commonly used by many other religions.  The use of incense in witchcraft is threefold:

 

1.  It conditions the mind by stimulating our senses of smell.

 

2.  In connection with spells, it draws down the spirits through its magickal association with the element of Air.

 

3.  According to ancient beliefs, when a spell is done, it raises the spell up into the ether and sends it on its way.

 

In magick, the type of incense used needs to correspond with the nature of the spell being worked.  Most spells require an incense associated with a particular planet or deity.  Many are used for their purification and cleansing properties during a ritual.