I just was reminded of important tip - trace the family group for more information on your family. The idea of a "FAN club" has been well explained by Elizabeth Shown Mills (you can see her explanation here). I applied the idea in looking for a Luxembourger ancestor who "appears" in the United States in the early 1870s. Despite my best efforts, I've been unable to find her immigration record. I know she had several siblings immigrate to the United States. There was a slight chance they traveled together, so I decided to take a look. It was a dead end.
So why am I happy? Because in all my searching, I discovered that her siblings used a different version of the last name than the one we knew. On a whim, I pulled it into FamilySearch. Bingo! I now have the date of her marriage - and more details than just the year!