In the order of the Seder as it appears in the ceremonial symbols, the afikoman is referred to by the word Tzafun, hidden, because it has been hidden away, from the beginning of the meal until the crane for eating it.
Some people hide it in a pillow or cushion; Rokeach mentions that the custom of hiding it inside the cushion used for reclining may have a basis in the verse (Psalms 31:20): How great is the goodness that You have hidden for those who fear You. We hide it in cushions to symbolically guard it, in fulfillment of the verse (Exodus 17): And you shall guard the matzot.
Many customs are associated with the afikoman. Some have a tradition of taking a staff in hand and eating the afikoman in great haste, in fulfillment of the verse (ibid. :11): Thus shall you eat it [the Paschal offering]: your loins girded, your shoes on your feet, your staff in hand, and you shall eat it in great haste.
It is a widespread custom in the Land of Israel to take the larger section of the middle matzah for the afikoman and wrap it in a white cloth. This is placed on the right shoulder and transferred to the left shoulder.
It is thus passed around the table from one to the other, the last one receiving it reciting the verse (ibid. :34): Their kneading trays were bound in cloths on their shoulders.
He then takes four paces and is asked: "Where have you come from?" to which he responds: "From Egypt."
"And where are you going?" "To Jerusalem."
Then all raise their voices and declare together: "Next year in Jerusalem!"
In some Sephardic communities, when they get to the point in the Seder for yachatz, instead of hiding the aifkoman, it is tied on the shoulder of a child, who leaves the room and then knocks on the door. He is asked:
"Who are you?" to which he responds: "Israel."
"Where have you come from?" "From Egypt."
"Where are you going?" "To Jerusalem."
"What are you carrying?" "Matzah."
The child then enters the room, looks at the festive table, and begins to ask the Four Questions: "Why is this night different from other nights?" and so forth.
The afikoman remains on his shoulder until it is time for it to be eaten.