Resist the temptation to skip verification of information between generations or sources. Since people often attend the funeral for their grandparent they don't worry about ordering the death certificate. They then spend years seeking a maiden name for the person's mother. Later they discover that the death certificate recorded the maiden name all along because it had been provided by the person in their medical records prior to their death.

For example, by finding the birth place of an individual, in order to verify information, you may also find his parents' names. The goal here is to obtain primary sources for your information and the supplemental clues they provide. If you only have "hearsay" evidence from a published family history, you should make it your goal to verify what you have.