What, specifically, can be done in terms of verbal and non-verbal communications to create and maintain rapport is something best experienced in real life and not put into electronic words. The analogy I often use is this one - when someone learns to drive they first learn the basics of steering, gears and brakes. When they have basic competence with these then they go on to learn more advanced skills. This would be like trying to get the learner driver to master the steering wheel before explaining what the gear shift is for. Training is more effective when the material is presented in a manner which matches the way people learn and understand.
Different people approach learning in different ways.
One of the challenges in training is to accommodate so many different styles. I approach this by starting with an overview illustrated with examples of specific details. As I progress I include more detail and combine details into bigger chunks. Some people prefer to listen to a verbal description and others prefer illustrations - so I talk a lot as well as writing and illustrating what I say on a flip chart. There's a whole section in NLP devoted to describing these different patterns, the different ways in which people organise their experiences.