Be a record sweep

This is what is meant by sweeping records. Often people jump back to far too soon in their research, and they loose the trail. A good researcher is like a detective who talks to everyone and looks in every possible place for clues. Each finding is a puzzle piece that fills in a little more of the picture.
Search collateral lines
A common mistake that researchers make is that they only search for resources to document their own ancestor. If their ancestor had siblings or cousins, that opens up other possibilities for finding links back to a common ancestor. If you have run out of resources to identify an ancestor, why not try searching for resources on your ancestor's siblings or other individuals on collateral lines?
Complete a family group sheet so you will have a record of parents and siblings. This a handy reference in case you do not find enough resources on your ancestor. Also, your ancestor may not appear on a census or other document you are using. Knowing other members of the family group will help.
Documenting birth
Since the death and marriage of Emory Wallace Vance (1901-1973) has been successfully documented. Check FamilySearch Wiki to determine if a birth record would exist for Emory who was born in 1901 in South Carolina. Search using the words "South Carolina Vital Records."
With a few exceptions, birth records were not recorded until 1915 according to “South Carolina Vital Records.” It was discovered that Emory is listed on the Social Security Death Index (SSDI). The original Social Security Application would have more useful information for a genealogist such as birth date, birth place, and parent's names. “U. S. Social Security Records for Genealogists” explains how to order a copy of the original Social Security Application.