One concern about the informal and non-hierarchical approach used in most campus fossil fuel divestment campaigns, and in the climate activist movement more broadly, is that it impairs institutional memory and thus prevents people from having a strong understanding of what has already been done and learned.
In an effective and intriguing effort to counter that concern the Fossil Free Macalester in Minnesota released a 29-page handbook: Handbook: Lessons from a Divestment Campaign.
It’s hosted on a Google Drive account (another challenge for institutional memory) but if that link breaks there is a backup on the Wayback Machine.