The biggest difficulty I found as an MSI tutor was getting the participation of my students. I find that the best way to combat a lack of interaction is to work in small groups, be amiable with your students and to try to make them laugh. Making analogies between the material you are tutoring (physics, for me) and some other part of the world is the surest and most effective way to make your students laugh. For example, today I compared the behavior of charges in a circuit to splitting one pile of burnt onions into two piles of burnt onions.
You may find yourself in a situation where you do not know exactly what to do to solve a problem. Do not worry. Have your students work it out. You not knowing what to do (or perhaps pretending not to know) forces your students give you feedback on how to solve a problem. Showing that you need their help gives them confidence, a trait that should be taught by their tutors. Having them teach the material back to you is great practice for exams, when they won’t have you there to help. They should not be too dependent on your feedback of their work.