Certified Flight Instructor Program:

A Certified Flight Instructor rating is required in order to teach students, and many pilots start their helicopter flying careers as flight instructors. During this training you will become even more proficient in your flying, and you will practice talking through and demonstrating the maneuvers as you would when teaching a student.

The amount of additional flight time for most students is minimal, but you can plan on a lot more "homework", as the FAA's Oral Examination for CFI is very challenging.