Best Practices for Unsub campaigns for tracking

hi all, 

I am curious how people set up their smart campaigns in the channel campaign.  Is it considered best practice to build an unsubscribe campaign that tracks the people who click the unsub link in that particular email?  Or is the best way to set it up in terms of structure is to not track per campaign since Marketo tracks unsubscribes anyway?

Would be solely based on reporting why the additional campaign is set up?

I am seeing that this is done in many ways but in terms of best practice, I would love to hear others thoughts.