Below are some of the important principles and experiences that guided SACO, quoted from: Miles, M. E., 1967, A different kind of war: Doubleday & Co, Garden City, NY. 629 p.

    There never was a military camp just like our headquarters. We hoisted no flag. We sounded no calls. We practiced no salutes and we wore what was handy. We walked, hiked, and scrambled, but we never marched. It was the place to forget spit and polish but never cleanliness—to forget rank but not discipline. Even I did what I could to be indistinguishable among the rest.

    The surprising thing was that it worked. The valley really served its purpose, which was to train guerrilla leaders and teachers, sabotage and demolition experts, solitary coast watchers, and weather reporters who were destined for lonely, isolated spots in a strange land. (Miles, 1967, p 137)

    In our SACO units the best-qualified man—whether Chinese or American—became the head of the section. Chinese took orders from Americans, and Americans from Chinese. And each side was always protected by its right of veto. This kind of arrangement could, I suppose, have led to an impasse, but with mutual trust it led with remarkable consistency to satisfying action. The system worked. (Miles, 1967, p 174)

    There was no rule book for operations such as these. The boys wrote their own as a result of trial and error, knowing that good men dead were the price of their mistakes. It was obvious from Lieutenant Hull’s reports that he took for granted the fundamental SACO idea that in China the Chinese must run their own show. On the other hand, he had discovered how Americans could strengthen them, not only with technical know-how but also in timing and by building the confidence of the troops.
His list of essentials was as follows:
  “Divide into small groups so as to move easily through surrounding Japanese.
  “Know the terrain thoroughly.
  “Gain the complete cooperation of the civilians.
  “Pick jobs that are the right size for the men available.
  “Look for Americans who are a combination of marine, raider, and quartermaster—men who can learn to care for themselves and their weapons in snow, rain, cold, or sun.
  “Have complete confidence in the Chinese guerrilla.”
Perhaps this final item was the most important one of all, though Lieutenant John R. Horton, USNR, added a most useful suggestion—“Work with the pliant younger Chinese officers—the colonels rather than the generals.” (Miles, 1967, p 385-86)