We ask our actors to sell tickets, and have a contest to encourage them to do so.  We also have a "box office" (local library) where tickets can be purchased.  Otherwise, tickets are available at the door.  We also ask parents (our actors are youth) to sign-up to "work" our shows ... backstage, costuming, sound board, ticket takers, etc. and spell out the requirements.  So far, no one hasn't signed up to help out.  Usually people are more than willing if you ask.