What could the British have done to prevent the American colonies from revolting?

Answers to this question inevitably venture widely into alternative history. 
Perhaps the simplest answer is something along the lines of this: Lord North, the British Prime Minister [1770-83], could have prevented the Coercive Acts and adopted a more lenient attitude toward the new world. Perhaps, this would have allowed the spirits of the colonist’s time to calm and prevented escalation after the Boston Tea Party.
Additionally, many argue that the relationship between England and the colonies would need to be more normalized.  Perhaps the American colonies could have been integrated into the commonwealth one hundred and fifty years before its founding. A plan to create districts in the Americas and establish American members of the House of Commons, along with establishing a landed gentry class to fill new slots in the House of Lords, could have rectified the "no taxation without representation" argument.  By establishing a "normal" English government, and by eliminating the Royal Governors in the colonies, the British empire could have become unrivaled in its strength.