The most important element of having effective multicultural discussions is creating an environment where discussions can flow freely. People have their own heuristics and stereotypes that they cling to. To learn to break through these, they need to feel comfortable that they are in a setting that's free of judgment and ridicule.
While teachers are considered to be practicing "experts" in their field of study, it can be effective to bring in someone indigenous to the culture that you are examining. This person can provide insight into cultural practices and beliefs, as well as a more personalized application of these ideas.
A facilitator can provide an assignment and then randomly assign students to groups to complete the assignment. Because of the social interaction necessary for task completion, students will tend to learn from each other.
Teachers should work into their curricula opportunities for students to experience different cultures. This can be done in a number of ways, such as through theatrical performances and art exhibits. After the cultural exposure, teachers can facilitate a class discussion about students' observations.
Students can act out different elements of other cultures during role play. This enhances their ability to overcome their preconceived notions, and thus promotes greater understanding. Again, an environment of tolerance and comfort is necessary for this to occur.