When writing about a relative, use more than just a title such as Aunt/Uncle, Grandma, etc. Grandma Neill or Grandpa Rampley can be equally vague. Also avoid using the title and just the first name. In some families, Uncle Cecil or Aunt Ruth can easily refer to more than one person. I had two uncle Cecils and three Aunt Ruths without having to reach into the distant past of my family tree.
Sometimes even the last name will not be enough help. There were two Aunt Ruth Ufkeses in my family, although one was always referred to as Ruthie.
Use either a maiden name in parenthesis, a middle name, or additional clarifying verbiage (year of birth and deaths) when referring to these individuals in writing–especially on photographs. When writing it’s usually sufficient to clearly identify the person once and them just make certain later references are clear.
And don’t get me started on Cousin Fred because I do not know which one you are talking about.