Otherwise, you're opening a can of worm for many excuses you end up paying for.

One of my favorite quotes from I don't remember where is - "This is not an excuse contest."

Now if someone is moving from Michigan, that can be a legitimate excuse, but it's something to consider...One quick idea..  

I ended up mowing it a couple times because there was literally nothing I could do to make them cut it and they always had an excuse.  

If they are power hogs or water wasters let them deal with the bills themselves.Trash should be the only thing covered by rent to insure service every week and doesn't get stopped by non payment.Don't give them an excuse to let garbage pile up and attract insects and government fines.

You've just about got it figured out, and you didn't lose the farm during your learning curve.You learn not to cave to excuses.  

I have been railing against this policy for quite a while that some selfish, self centered landlords try to justify with the lame excuse that "it's just business"!  

I can't imagine driving to each property to collect cash, some people will have excuses instead of cash, then you have to drive back out. 

If they say they're ok to stay during remodel, say your insurance won't allow it, or whatever excuse you need (that isn't your/their fault). 

They'll have no excuses not to pay or be able to say it was 'lost in the mail'.