I have never handled transitions graciously.
I'm hitting that strange age when I'm no longer a child, but not quite a full-fledged adult, either. Dealing with aunts and uncles, I still struggle with what to call them. Is it Uncle Rich, or just Richard? Aunt Sue, or Susie? At twenty-two, it feels more natural to just use my aunts and uncles' first names, but there is that sticky transition.
Grandparents, of course, will always be Grandpa and Grandma. Great aunts and uncles are the same---Aunt Becky and Uncle Alan. It just shows respect.
How do you address your relatives?