For me it's names that work just as well on an old person as they do on a baby.
So for boys: Jack, Harry, William, George.
Girls: Lily, Grace, Rose, Harriet.
Personally I really like timeless names as opposed to trendy names that come and go. For example, round here there was a massive surge of Jayden's, Kadens and Harley's. But you'd never see that name on an old man.
It's strange because a lot of the timeless names are constantly in the top 10 too. So you could class them as trendy and I guess.