It’s important to set aside time to update your family tree by adding source citations to information that does not have any.
If you have been researching for a long time or have not been conscientious about adding sources as you go, then you may have a lot of work to catch up on. To make this seemingly endless task achievable, you should break it into smaller chunks – perhaps one hour a week or fortnight. Don’t forget to measure your progress – seeing that number of missing source citations dropping is motivation to keep at it!
If you use family history software, you should be able to find a feature that tells you which information in your tree currently has no source citations attached. In Legacy, for example, under the Search tab select Find, then select Missing Sources. You can search for people who have no sources, or are missing source citations on one or more items. You can also narrow your search for people who are missing specific types of source citations, such as sources for the death date and place. Click on Create List to generate a list. You can work through the list from this interface, or click the Options button then select Print. That gives you the option of saving the list as a PDF or as a CSV file. I prefer the CSV format because I can open it in Excel and mark them off as I complete the citations.
If your tree is online with Ancestry, FamilySearch or another site, you will need to impose your own structure to work through your tree systematically adding source citations. One way to make it manageable might be to work on one surname at a time, starting from yourself and working backwards in time.
Of course not all sources are equal in quality and there is also the question of how many sources you need to cite, but those are issues for discussion at another time. One source is better than none, two independent sources are better, and if you find more then it’s time to celebrate.
Choose a method works for you and get stuck into it. The benefits are worth it!