Things like CCTV cameras, signage and exterior lighting go a long way with tenants.

I use a lock box, Wi-Fi thermostats and a security camera I can check on remotely.

In summary, the main building:1) will need to be tented for termites/ants,2) will need basically two full bathroom renovations (floor around one toilet is a bit soft and rotted some of the joist down below, and the other bathroom is an addition that looks like it also might not have been built to code bc has really tight spacing and has a huge crack in the walk-in shower that basically just drains water out into the crawl space below the house and the floor under that area is just totally rotted out),3) would need a refreshed kitchen (sink drain plumbing is in need of repair and at a minimum would need new countertops but likely new cabinets as well)4) they recommended earthquake bracing to the foundation since it’s almost a 100-year-old house and reinforcing part of the cripple wall down below5) found a clog (or at least an area the camera couldn’t get past) in the sewer line.

As off-cast cell phones come up hourly while your neighbors do their annual upgrade, you can have something personal with a camera and wifi (which works from the library, public stores and many other locations 24/7), you can open that ebay account and craigslist to sell off your freebie items gathered from society's refuse.  

@Andrew ReisPut a camera in the stairwells I bet they are smoking in the stairwells if they are smokers.

We use Minut for indoor monitoring, and exterior Ring cameras for exterior monitoring!

You can offer your tenant some security cameras.

If the sewer was just cleared but not fully repaired I would get a scope (camera Recording) of it before you move on.

Will be installing fencing and camera system.

I also make sure to have a security camera system at the self-storage facilities that are linked to an app that I can view remotely or on my phone.