Constant positive motivation is the key to the success of your group. The Peer Educator, the monthly newsletter, with prospective members. Offer the Certified Peer Educator training on your campus to your members and their friends. Then let them put their new skills into action. Establish a point system for members, one that offers them the chance to attend trainings, win prizes or awards.
Friendly competition can provide excellent motivation.
Invite a motivational speaker to address your leaders and the leaders of other student groups and organizations on campus. Expect the best from people you lead. If you establish high but realistic expectations, you give your group an achievable goal. Make a thorough study of the members' needs. Then match their needs to the groups needs.