Would it be possible for someone to list the best practices based of this thread i.e. what to check, inspect and possible fix before the pre-test. Would be a big help...

Where will you be tested and do you know the extent of the test? I used to test in Oregon and they only did two things - checked for a catalytic converter and measured idle emissions.

Some areas do complete visual inspections, and test idle and 2500 RPM under-load emissions.