Recently I watched a video about ancestors; I think it was from the Pagan Perspective channel on YouTube. I reminded myself of the video I had watched and it got me thinking about ancestor veneration. There is a number of dates of note dealing with ancestors, Samhain, Day of the Dead, Qingming Festival and Ghost Month.
A personal belief is of rebirth, leaving the question of why to venerate after a certain amount of time. It is also viewed that even after rebirth, a part of the person stays behind leaving them able to bring blessing or possibly even the opposite, leaving ancestor veneration of some significance. Personally it is however not just about trying to appease, but also to remember them.
This leaves is to give regular offerings that only really need to be some incense and a candle or two to be lit for a small amount of time. Offerings of foods and liquids boil down to who the ancestors are, with how the altar looks also being part of whom the ancestors personally are.
How one venerates their ancestors can vary a number of ways, the most notable is the times of the year take of most importance in remembering and venerating ancestors. It can also only be only a particular day or two of the year, a weekly basis or a daily basis, depending on practice. When one looks at it, asking people on what they do can tell plenty.