Generally I think planning for 20% vacancy when starting out is smart as it can take some time to get traction on your property and aiming for 1.5 to 2 times the LTR rate. 

Note:  Been pounding the table to BUY SMART any real estate since 2010.

It's not to say that you can't lock something down with an FHA loan, but you have to be smart about your approach and be open to compromising.

That to me is business smarts not book smarts. 

If the tenant is smart, they know they can take you through housing court for this and just simply stop paying any/all rent & fees owed. 

Here are a few suggestions on how you can maximize the wealth of information available: Check out the blogs and podcasts, or take advantage of the search feature (magnifying glass).

There is a lot of good, smart financial reasons to keep great tenants.   

Ask smart questions, do research on your area, don't ask anyone to be your mentor.

Recognizing and acting on them in a smart manner is the challenge  Here is another prediction, those that recognize the value in my post already have a plethora of opportunities.  

The rich get richer, and like George Carlen said--it's a great big club...But given that....don't see the glass as half empty, instead see it as half full.If you want to be a big fish (accredited investor) RISK your investment money in things you think will get you to that goal.