From what I know from my grand dad, at least the Quang Liang people, there is a communal altar, where generally every family would bring extra food. These are the family less souls, or those who died without burial who have become Kuai Zais aka homeless ghosts. (Guess who ends up eating them? The grave construction workers.)
My Ah Kung was baptised, we went to visit the grave with white candles and flowers, but we also bought some oranges for us while we were there. Ah Kung told us eat throw some peels and orange segments around the tomb. This is done in the hope that the Kuai Zai won't come inside the tomb area and snatch the food.
For many years before my Ah Kung died, the clan had bought a hill for their cemetery, and we had Ah Kung's tomb prepared. Every Ching Ming aka grave visiting day, he took us there. He told us, when I am alive, if you guys don't go, needless to say, after I had died.