At Agile 2010, David Spann and Gil Broza gave a workshop on agile coaching. The workshop involved several exercises to stress the importance of presence, curiosity and empathy.
They started out by emphasizing the importance of good posture when engaging a client. Posture subconsciously sends message of energy and others will check in or check out based on that. When standing, stand in with right foot in and always feel your toes. When sitting, sit up straight and also feel your toes. If things are not going your way, know your presence and adjust accordingly. They also reminded us that standing up is a power high energy position. It means you are involved.
Next, David and Gil define empathy as repeating in your own words what was said, mirroring hand gestures, and not trying to pass judgment at the moment of interaction.
Finally, curiosity involves asking questions and figuring out the context. They wrap up by recommending several books:
Presence Based Coaching
Leadership Dojo
Coaching with NLP