Sharon Tate Moody, in a recent edition of TBO.com, published a good article on the application of common sense to genealogy research.
It's an informative article on its face, but even more so when you realize that she is also urging us to take a step back from our research and take a total life view of the ancestor under investigation. Look at birth date, death date, date of children's births, date of marriage, major events in the world and the age of the ancestor when they occurred, etc. This "macro-view" can help set the stage for applying the common sense she talks about. For example did the ancestor die three years before the birth of his child? Was he only three years old when we got married? A little common sense will identify inconsistencies like these.
You can read Sharon's article at? http://www2.tbo.com/content/2010/may/30/tr-common-sense-can-help-you-keep-research-sane/life/