our organisation is having difficulty cultivating trusted volunteers.

Our mission and circumstances is very appealling, so we attract many new volunteers, but we have a dearth of people transitioning to trusted volunteer status.

Also, the allure of personal gain trends to attract problematic, opportunistic types, to the leadership position,although this may be a peculiarly Australian problem given our convict/colonist background.

I understand that not everyone takes up the vocation, it is a choice with what one does with their spare time. 

What are the circumstances / structure that your organisation has to support your lead volunteers?

On a personal note, what prompted to to take up the mantle of leadership? What keeps you doing it?