I only have one unit, but I lived in Thailand for 4 years and I managed the property myself. I am happy to talk with you. First off, I take care of my building top notch. I also have an excellent relationship with my tenants.
The first thing I do is I pay for extended warranties on all the appliances. I know people do not recommend extended warranties, but this may it so easy for my tenants. My tenants would call the service provider and wait for the service personnel.
The second thing I did was I provided to my tenants the name of my preferred plumber, electrician, hot water heater repair, roto-rooter type company and handyman. My tenants were directed to contact me first, yet if there was an emergency they could contact the repair companies. I also have an excellent relationship with the repair companies and they they have authorization from me to spend $200, and everything beyond that they must get written authorization to proceed.
I also provide my tenants a monthly good will rent reduction. Every single month, I provide them to good will payment, and I label it as a good will payment. They know that I am giving them the good will "rent reduction" in exchange for when stuff happens they will work with me to get things done. Paying them a "good will" payment every month is significantly less than paying for a property manager. I would typically provide a $75/month good will payment.