- Surname variant spellings.
- Age when first married: what's usual in your family line? in mine it's between 15 and 25, usually.
- Locations. People didn't move so often or so far. But, then there were those who did.
- Middle names. Some people preferred their middle name to their first name, as in my maternal great grandfather who was Thomas James but always called James.
- There's almost always at least one other person with the same name, somewhere. Don't jump to the conclusion that you've found the person you're looking for until you've found corroborating evidence.
I love doing family history research. It's like being a detective or doing a large, complex jigsaw puzzle.