4. Make it interactive. The straight lecture-only type classes will rarely get the job done these days. Work on exercises, drills, and role-plays that get the student involved in the class and help them learn by doing. Keep it light. In a classroom environment, humor almost always helps.
People retain more and learn more if they are relaxed and having fun.
Even the most serious training programs benefit from a good dose of humor. Just make sure it's appropriate. Hold the training in the proper environment. It's hard to learn if you're uncomfortable, regardless of how good a course may be. Find the perfect place to conduct the training.