Your grandpa’s old hammer still works. Build things that are useful enough to pass down.

Objects made to be used, rather than admired or replaced, tend to last for generations. Usefulness is what earns something a place in the next household, and it is a far lower bar than beauty or importance. The same rule applies to things that are not objects.

Ask what you are making that somebody could still use in forty years. A tool, a recipe written down properly, a way of doing something that reliably works. Build one of them to a standard that would survive being handed over.