Create or attend pre-enrollment information/advising sessions.
Create and distribute a survey to majors/minors to learn what they most appreciate or most want to change in your department/program, and present the findings at a department/program meeting.
Organize a research panel; include information/speakers on research, internship and other academic opportunities.
Organize a series of brown bag lunches on topics related to your department/program or to your general field of study.
Organize a "What to Do with a Major" event; invite alums with a range of professions.
Discuss your recruitment ideas to attract prospective majors/minors with faculty.
Help establish tutoring groups or study sessions.
Lobby for new course offerings.
Organize a graduate school information session.
Organize an alumni career panel.
Organize thesis writing sessions so students can support and learn from each other.
Plan movie nights, talent shows, ice cream socials, etc.