Use a property management company or hire someone. Once you have a few, the cost begin to get spread out so it effects the margins less.
I live 400 miles away from every property I own. I do stay in Columbus about 3 months out of the year but that is totally do to my second office there and has nothing to do with the properties.
They check on the roof, mow the grass, fix the lights, change the batteries in the smoke detectors and collect rent for me via their website or mail in payments. They then send me an invoice each month and at the end of the year which I then hand to my accountant for taxes.
I haven’t even known who my tenants are for years.