T, I suppose there could be any number of differnt sorts of answers to your question and the usefulness of these will some times depend on your location as wellas the nature of the deer, Muleies, Whitetail, Cues etc.
Now one generic answer would be; that as trappers we return to the same (exact) location day after day and closely evaluate things. To trap sucessfully you must consider all species not just the target critters, e.g., it doesn't do much good to make a trail set in a well used deer trail.
I think, as a trapper, I have learned to fine tune my observation skills and through trial and error, come to better understand the way things work, especially on my lines and generally in my country. Now, if I want to kill a nice buck, I just know where they tend to hang and move, simply, because I am out there day after day in some cases for 4 to 6 consecutive weeks.
I don't want to imply that I can go out and kill a buck every year, for, unfortunately, we just don't have many deer. But boy howdy if you want a bull, that might just be another issue; if I can draw a tag.