We observe.

Just offering what I observed ...

I don't use a property manager so I cannot give feedback on one specific company over another, but based on my observations over the years there are a lot of student rentals that are poorly managed and in bad shape.  

Then observing and guiding tenants back to the terms of the rental agreement if they stray.

Showing: If the prospective tenants pass that stage, we invite them to see the property, at which time we observe and find out more about the prospective tenant.

And sites like padmapper and zilpy, and zilliow and Craigslist help to do that survey; I bookmark the search for those so that when the time to increase comes along, I click the bookmarks and observe the competition in the market. 

I've instructed the tenant to file a report if any illegal activity is observed and to take photos of the issue and send them to me.

Have you observed them walk; if so, how is their gait pattern? 

Also, for moral compass type questions an in-person interview would be best so both the verbal and non-verbal communication can be observed.  

Be prepared to observe:* Demeanor, interpersonal skills, communication style.