Ours meet about once a half term...usually in a registration session or PSE lesson, they act as a kind of student voice mainly so taking concerns from their tutor group to the meeting and feeding back. The students often get fixated on uniform issues and other non-negotiables so need directing but they also talk about what they would like to spend PSA funds on, or how they would like a new part of the grounds used/designed or whatever else might need a student vote and sometimes get a new "rule" passed for example, use of phones for music at lunchtime maybe? - so they learn to have reasoned arguments etc. We also have two yr 11 ones represent the students on the PSA (hence we call it PSSA -parent, staff, student assoc.) - they attend meetings and have to act as adults would so great experience and they then feedback to the council, again great experience. They also do things like new parent tours on prospective parents evening etc sometimes.