In the one tour I did last year I noticed that the first five miles resembled the "highway Of Hell" of Basra during the First Gulf War: the roadway was littered with broken down bikes that hadn't so much had seen a drop of WD-40 in the last five years, with riders having sprinted full blast like it was the last 500 meters of a TdF leg and were gasping for air and asking to be killed on the spot to be put out of their misery.
So I guess one of the keys is to either go out fast with a lead group, or go out very slowly and hope to survive the harsh Darwinian process of group riding dynamics.