We use what is basically the "GitHub" flow... forks and PRs on an instance of GitHub enterprise. This is nice because in addition to the isolation it provides

We use what is basically the "GitHub" flow... forks and PRs on an instance of GitHub enterprise. This is nice because in addition to the isolation it provides when everyone is working on their own fork it's easy to code review changes BEFORE they land in the "blessed" repository. It's also nice because junior developers aren't pushing directly to the blessed repo either. This model is really nice for maintenance and small feature development. For major new development (new version, major feature that multiple people will work on) we tend to revert back to the behavior of committing directly to the blessed repo.