This method goes along with Gather All Clues. Now you need to focus on the details of each clue you have gathered. Sherlock was very detail oriented. He wanted to know who, what, when, where and why for every clue. When you are looking a document, you will understand it better if you answer these questions:
"Who created this document?"
"Why was the document created?"
"When was the document created?" (not only the date but put the document in context of the entire record set and in context of what was going on at that place and time)
"Who are all of these other people mentioned?" (how do they relate to each other)
"Are there other documents that could shed light on this one?"
"It has long been an axiom of mine that the little things are infinitely the most important.” [Holmes to client Miss Mary Sutherland, "A Case of Identity"]
“It is, of course, a trifle, but there is nothing so important as trifles." [Holmes to client Mrs. St. Clair, "The Man with the Twisted Lip"]