The role of mundane activities is interesting: A cup of tea, reading the newspaper, taking a walk, smoking a cigar, etc.<p>People who have trouble sleeping are, among other things, supposed to establish a routine. Repeating mundane activities (brush teeth, lock doors, turn down thermostat, etc) in the same way every night seems to prime the brain for sleep.<p>I suspect it doesn't matter <i>what</i> you do before you settle in to work, simply that you establish some "it's time to work now" cues and then take advantage of them.