Asking relatives questions is one way to elicit family stories and traditions of which you were never aware. But often copies of family pictures or other family memorabilia is an even better way to stir memories.
I recently shared to my personal Facebook page a copy of letter our aunt wrote when applying for a job in the 1960s. Two of my cousins responded with details of which I was unaware–based on the letter. The aunt’s address and other details in the letter brough back memories that pictures apparently did not.