Navigating the name game

I come from a big clan that likes to apply the term "family" very generously. For many Beijingers and other Chinese urban dwellers, a family dinner means sitting down with mom, dad, grandma, grandpa, perhaps an uncle or two, and maybe some in-laws. But back home in the northeastern countryside, getting the family together meant I would be greeting relatives as tenuously tied to me as my grandmother's cousin's grandchildren or my mother's brother's brother-in-law.
As you can guess, one problem with a large jolly family is that it requires one to learn how to address all the random relations. In a Confucian society, filial piety and respect for the proper order of things are of supreme importance, so it's not as simple as calling a man "uncle," a woman "aunt," and everyone else directly by their name.
To cope with the problem of what to call my many relatives, I devised simple rules as a child. At the frequent family reunions on my mother's side, any male over 1.8 meters tall with hardy features was likely related to me by blood, so I would call him jiu (maternal uncle). Any female meeting a lower, but still relatively high, height requirement would be a yi (maternal aunt). Males and females not bearing strong physical resemblance to us were probably related to me by marriage, so I would call them yi fu (husband of maternal aunt) and jiu ma (wife of maternal uncle), to be safe.