Take the GMAT exam. Although teaching GMAT courses does not necessarily require taking the course, it is suggested that you take the test as well as any other study courses in order to familiarize yourself with the content.
Research some practical testing strategies. They include, but are not limited to getting a good night's rest, proper study habits and using the process of elimination.
Contact area tutoring services that offer teaching opportunities for GMAT instructors. Popular organizations that offer these services include Kaplan and Princeton Review.
Market your services online and on university campuses. If you do not wish to be bound by agreement through a formal employer, you can tutor students independently to students in college or working professionals. Create and post ads online and around campus with your desired rates and teaching experience.
Build a list of clients that will refer you to other clients. Hopefully, your strategies will produce optimal scores on the GMAT exam. However, please encourage your students to study independently as well.