You can also hire out the work but if you don't understand what can be done and how to do it, you usually end up building your custom software several times and the ROI goes out the window.There are some good off-the-shelf solutions as mentioned though, which is a great option if you don't want to DIY. 

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.  

It's a book that never finds it way back to the book shelf.

Shelf is empty.

The rest is going to the shelf until you sell it.If you are already working full time on another income, It's very tough to convince IRS that you qualify for 25K allowance since you need to actively participate 500 hours.