Identify the job to be done. Put it in writing so that you have a clear vision of what needs doing. Select the best person or group for the job. List the qualities and experience you desire. Link the desired outcome with the individual's motivator.
Motivation is no secret weapon.
Everything we do is based on motivation. Plan annual ceremonies to recognize volunteers. Rely on them in an emergency situation. Give them the honor of meeting with higher-ups. Recognize personal needs and problems.