One of the most common things I hear from individuals is that all their ancestors have been found. I have yet to ever to find someone for whom it is true that all their ancestors have been found. From an ancestral perspective at 10 generations we each have 256 ancestors. If you include their children and spouses the number is more likely to be about 2,000.
The most powerful way to research, however is descendancy. If you think about what our ancestors care about, it is their families. They would be interested in us finding all of their descendants. It is also a richer field for research.
The same ten generations that generate only about 2,000 individuals will have more than 5 million descendants. Unless your tree has this number of individuals in it then there is likely work to be done.
Descendancy has been more complicated to do, however. Finding the lines that need more research can be challenging. A new website, puzzilla.org, can help.
When you visit Puzilla you can log on with your FamilySearch account. You will see a wire frame view of your fan chart. Once you select an ancestor it will redraw and show you their descendants. You can then look for individuals who lived to be an adult, but have no children. This is a great place to research. You can also look for individuals that have large gaps between children where there is likely an undiscovered child.
Once you find someone you can click on them. It will take you to the person view of the individual in the Family Tree on FamilySearch. Click the search records and the fun really begins. I have a well researched family tree, but I found a new relative that was not in the tree in only twenty minutes using this technique. Give it a try. I think you’ll have great results.