What strategy worked well for the colonists in fighting the british during the american revolution?

It was the strategy of Attrition.

Washington saw, particularly after the fall of New York in 1776, that, despite the fact that his little armed force couldn't guard every one of the urban areas in America, its presence only guaranteed that the revolution would proceed. Without a genuine normal armed force, he stayed away from any definitive conflict with the expert English forces in favor of a strategy of attrition, fighting just when the chances were unmistakably to support him.