Garuḍa Purāṇa 4

After ascertaining the death of a person, his son should proceed with last rites to the body.  As the first step towards the last rites, the corpse should be washed with water and it’s (he or she has now become it) clothes should be replaced with new ones. In all the annual ceremonies for ancestors, immediate three ancestors are invoked.  For example, during annual ceremony of one’s father, father, father’s father (grandfather) and great grandfather are invoked.  However, while performing the last rites to a corpse, rites are performed only to the deceased person alone.  This rite is called ekoddiṣṭa śrāddha. Then the body is taken to the burning ground.

While carrying a corpse from the place of death to the burning ground, śrāddha ceremonies are performed at six places and they are – at the place of death, at the main door, at the cross roads, at the burning ground and finally on the funeral pyre. The performance of these six ceremonies satisfies six gods.  Goddess earth is satisfied while performing rites at the place where the corpse is placed at home.  The corpse is known as śava at the place of death.  When the corpse is taken through the main doors of a place, it is called pāntha and Vāstu god is satisfied when this rite is performed. The ceremony at the cross roads is called khecara and the god Bhūta is satisfied because of this ceremony.  The corpse is known as bhūta at the place where it is placed in the burning ground before placing it on the pyre.  By performing a ceremony here, gods of ten quarters are satisfied (east, west, etc).  When the corpse is placed on the funeral pyre, it is known as sādhaka.  When the body is burnt into ashes, it is called preta.  In all these ceremonies, the head of the corpse should be on the southern side.    

Before the actual cremation begins, there is a ceremony called piṇḍa vidhi.  Piṇḍa is a ball of rice offered to the dead.  The departed soul is said to become a pitṛ (ancestors) by eating piṇḍa-s. It is said that if piṇḍa-s are not offered, they become demons (ghosts?).  The funeral pyre should be cleansed and the corpse is placed on the pyre and the fire is lit after worshipping Kravyāda (a type of fire god) who is supposed to consume the flesh of the corpse with a request to consume the flesh and carry the soul to the heaven.  When the fire is in full flames, oblations are offered with ghee and sesame seeds (also known as gingelly seeds) in the pyre.  After paying respects to the burning corpse, relatives leave the place, take bath and reach home only to return again the next day morning.

Next day morning, the remaining ashes are collected and transferred to an earthen pot and this ritual is called saṁcayana.  Ashes are collected in earthen pot and the pot is immersed in holy rivers or sea.  Then for the next ten days piṇḍa-s are offered to the preta (the corpse is now known as preta) along with water.  This ten day period is called āśauca (āśauca mean impurity).  During these ten days a preta body is formed.  For example, head of the preta is formed on the first day, second day piṇḍa forms neck and shoulders and so on.  On offering the tenth day piṇḍa, the complete preta body is formed.  Preta can be explained as the disembodied spirit.  Only when the preta is properly formed and nourished, transmigration of the soul within the disembodied spirit is not possible.  Garuḍa Purāṇa discusses about preta elaborately subsequently.  Five chapters out of the total of 49 chapters deal exclusively with preta-s.  

If a death is caused due to unnatural conditions, where the body of the dead could not be found, there is a procedure called Nārāyaṇa bali (bali means offering and Nārāyaṇa bali means, offerings to Lord Viṣṇu). By performing this ceremony, the dead gets preta body ready to be born again.