You can include following elements while auditing MR (QMS as a process):
1. Internal audits, its NC closure, effectiveness verification of last NCs (8.2.2, 8.2.2.4, etc.)
2. Management Review process (5.6)
3. Control Of documents (4.2.3)
4. Control of Records (4.2.4)
5. Analysis of data (8.4),
6. Customer requirements
7. Customer satisfaction
etc.
You should use process approach to audit the QMS process (auditing Input, output, resources required , skills required, effectiveness , efficiency of the process).
This is what we do....I hope this helps..
Thanks,
Amit