Working backwards from yourself to your most distant ancestors is a critical method in tracing one's own ancestry. Although it requires discipline, it is extremely important to systematically work backwards in time through the record trail, exhausting all record sources for each person, before working on their parents and grandparents. Without working systematically backwards, it becomes more and more easy to miss a crucial piece of evidence, or to rely on a hypothesis or guess as the foundation for later efforts. Use of a checklist for every person you are researching can make this methodical task easier.
In order to properly work backwards, one should use evidence in one generation regarding the previous generation as your foundation.
Birth, marriage, and death certificates, both civil and ecclesiastic, often name, or even describe the occupation of, the bride or groom's father and mother. Many times the certificate's subject's place of birth is given, and sometimes the place of the parents' birth as well. For example, old civil birth records (1865–1910) in New York City, found at the Municipal Archives, have a field for Father, Father's Place of Birth, Mother (with maiden name), and Mother's Place of Birth. Similarly, old ecclesiastic records from the villages around Kaiserslautern in southern Germany often describe the fathers of both groom and bride, the fathers' residences, and occupations. Less often in the oldest records, the mother is named. However, using either record, one would certainly establish a solid footing for looking into the previous generation.
However, a single record, such as a birth, is not enough if further records are available. If one readily finds the civil birth record, it can serve as a guide for the location of the same person's ecclesiastic baptismal, christening, or circumcision records, which may confirm, conflict, or expand upon the information in the civil record.
Further research should be conducted upon your subject, however. Marriage and death certificates and records, both civil and church, land records, coroner's reports, voter rolls, census returns, and numerous other pieces can add to your understanding of a person's parents and their history.
In many cases, you will find information about several different generations at the same time.