One of the most sacred rituals observed by all Jews throughout the generations is the practice of reciting the Kaddish prayer for those who have passed on from physical life.
Kaddish is recited for eleven months after death, and thereafter, each year on the yahrtzeit (anniversary) of the passing. It is a tremendous merit and source of elevation for the soul.
The ideal preference is that the children of the deceased recite Kaddish after their parents, three times daily, for the first eleven months after the passing. When this is not possible, or as a supplement or safeguard to that, another person can be hired to do so.
One time-honoured custom is to donate money to a charity that supports the poor and needy and, in return, Torah scholars recite the Kaddish in the merit of the deceased.