Be ethical by:
Keep up your units in good repair.
Be communicative with your tenants.
Respond to tenants complaints right away.
Learn how to fix and repair tasks yourself so you know what to expect from others.
Get licensed professionals to fix issues as electrician, plumber and others as it could cost you hugely if not.
Put in and keep up smoke detectors and have fire department check them.
Have correct notices visible and put u correct notices.
Have security patrol.
Correct lighting on outside of building.
Make sure you are paying common grounds utilities not your tenant.
Ask yourself 'do I really have time for management' and should I hire a management company.
Take classes on management that the city offers and not end up in Housing Mediation
Never threaten, stalk attack or harass your tenants.
Be aware tenant may have hidden cameras in their units. Never get into a tenants unit without them being present.