I have considered putting in a sky light but that could be costly.

With new bathroom, widening one bathroom door, upgrading a toilet in master, granite on kitchen island (had ugly tile), hardwood flooring, upgrading lighting in dining and kitchen to can LED lights and paint, we spent about $19K in upgrades.

.- bathroom sink ceramic paint are coming off- they want the garage door light to stay on after it opens up- pen marks on the bathroom vanities- light bulb needs to be replaced- nails on the wall

(light burned out under the over-the-range microwave -she actually waited for me to drive to the store and get the replacement!).  

@Steven Hamilton II can shed some light.

An additional note, entering a tenant's domicile should not be taken lightly.

I would install outside lights first and foremost and not the motion ones the timer ones.

.$200 "emergency" electrician call to flip the break to that one light (instead of the whole house).  

make sure they are not growing pot with 2000 watt grow lights

There is simply no way to be effective with extremely large lists (your just shooting in the dark) shed some light on that 20% and target what they want.