What is the polite/proper way to address elderly whom I am not familiar with? I was wondering what is the polite way to address elderlies I do not know. Take the following context for example. Perhaps I visit a store and there is an elderly woman running the register and I would like to ask for help.

I found this question and I think it may be related but I just wanted to clarify. Is it proper to say 老奶？and 老爸?
For an elderly woman, 大妈，大娘，大婶，阿婆，老奶奶 -- what's best really depends on what they are using locally and the age difference between you and the person.

You can always just say: 您好, if you are not sure what word to use.