Recruit or die. Any unit which is not recruiting new members is going to fade away. You always have members aging out. So recruiting it key to building membership.
But you also must retain those members. What is the key to keeping youth around? Program, program, program. This is also a good way to recruit members. If your program is fun, then your current members will invite their friends.
And then there is the job of recruiting adult leaders. How do you you engage the adults associated with your unit to get more involved?
Some additional articles about recruiting and retention are listed below. What are your ideas? Add them to the comments at the bottom.