Best Practices for Configuring Access Controls for Product Collaboration?

Hello,
We went live with Product Collaboration last Spring. We're now doing our second phase, in which we'll be controlling another level of more sensitive documents in Agile. We'd like to control these using Agile's ACCESS CONTROL fields. I haven't found much documentation, but was wondering if there were any best practices or tips and tricks on how to approach this? Any help would be great.

Thanks.