I have almost always used local guides in my trips - discovered through a variety of ways, from word of mouth and recommendations, from lists provided by some of the largest publications and organisations in the world and, sometimes, through my own personal research and vetting. It’s usually a long and very rigorous process based on a wide variety of layers, from the financial to the intuitive - from what a person says to how they respond to the details they readily provide. Some shine immediately as real stars - professional, responsive, detailed and with clear mastery of their area of coverage - others need a lot more filtering and communication.