Put in coin operated machines. 

Popcorn airpopper machine and small bags of kernels (super cheap)Non metal (not sharp) dart boardWalking sticksCheap binocularsFishing pole if you are near a creek/water (I am)

Get your initial investments to an infinite return state, which will start to generate momentum for you to expand your wealth machine. 

It went from things like wanting me to let them have a washing machine in the unit even though the owner said no to them and after I explained it's because the pipes can't handle it and sorry, I'm not losing my job over it for you (in a very nice way) -- furious reaction, no more friendship.... to wanting me to tell their neighbor to stop having such loud sex (not kidding) and when I said I don't tell other tenants how to have sex (again in a very nice way, while giggling no doubt), I lost that friendship. 

Now if I had another tenant ready to go and slot straight in, then sure, I would consider refunding him some rent. 

I leave a note in the door slot that says:  "Make sure you keep paying...We know where you live.   

I only sent out reminders because I had a lot of law students who would have the rent check sitting on their dresser, but they were so exhausted that they'd just forget to put it in the drop slot (the owner I worked for was old school and wasn't interested in online options).It seems like the only reason you need to contact your tenants is to tell them how much they owe in utilities. 

For instance, "I'm sorry, but our policy is that we don't allow portable washing machines in any of our units."

Sadly, you might need to explain to them how to use a washing machine and how much stuff you can put in it.

Run the machine empty using Finish machine cleaner (I give my tenants a couple and ask them to run it every few months).