I have been a graduate student instructor (GSI) for two courses: an introductory class targeted at first-year undergraduate students, most of whom did not intend to major in economics (Introduction to Environmental Economics and Policy, with Professor Keith Gilless), and an upper-level undergraduate class targeted at economics majors (International Trade, with Professor Ann Harrison).
I believe in learning-by-doing. I know from my own experience as a student that it is easier to follow along as an instructor explains a concept than it is to apply that concept to a practical problem. As such, I try to start each class with an individual or group exercise that asks students to apply a concept that they learned during the previous class. (Some examples of exercises I have used can be found here). My Statement of Teaching Philosophy describes my experiences as a graduate student instructor, and the types of classroom activities I encourage, in more detail.
I believe that my teaching methods, and my use of in-class exercises in particular, have been appreciated by students. In both classes, I received positive teaching evaluations. I also received Berkeley's Outstanding Graduate Student Instructor Award, which is given to the top 10% of graduate student instructors each year, as well as a Teaching Effectiveness Award for the teaching methods I implemented.