I typically have achieved infinite return on my BRRRRs, but BRRRRs are one of the least passive RE investment options. 

OK then.. which one would you have, free highly motivated, infinite ROI, all free, all effortless... or you knocking on doors on a cold December evening?

Well probability says, if you infinitely try to throw that brick as hard as you can in the water eventually you should get one.My point?

There are infinite steps you could take if you want to break down how to buy a vacation rental into the minutiae, but I'd follow the KISS model -- Keep It Simple Stupid. 

It'll get to market rent eventually, was more interested in a good relationship and no turn over)Submitted my rent increase and paperwork to section 8 (not real hard) Rent Increase was approvedNormally I would do a nice rehab..but it already had a paying tenant and was in "good enough" condition.My hopes were that it would appraise $100k+ and worst worst case a little higher than purchase price ,which, even then my ROI would be very high.Fast Forward 6 months...Appraisal comes in at $102kThrough the cash out refinance and 6 months of cash flow this was an infinite ROI deal as it put every penny back in my pocket (plus more) through a more unorthodox "sweat equity" method of buying a low demand, poorly marketing property with barriers to entry..

So even if I'm only making $1/mo, my cash-on-cash return is infinite while I'm enjoying principal reduction and tax benefits.In my experience single families tend to appreciate better than multis.  

If you initiate the proper due diligence in considering and selecting a mentor, your return on your investment is paramount and infinite.

What you want to do in order to amass wealth through rental properties is to get infinite ROI.

However, i've found that a small directional sign to a house available for rent is infinitely more tolerable by nearby homeowners and any code enforcement, especially if it looks like it was hand written, simply because it DOESN'T say any of the commonly offensive Sales Pitches (We Buy Houses, Free Cell Phone, Medicaid Prescription Coverage, etc).  

Assuming you are buying your properties right, you can then do a refi within 30 days and get all your money back, therefore giving yourself an infinite COC return because you have no cash in the deal!