Is there a method that you recommend when it comes to assessing whether there is a good rental demand in any given area?

I'm starting to look for more creative financing methods especially given the market is starting to shift - and trying to figure out the "how" to make deals work as opposed to just leaving it once a traditional method doesn't work out.

@Jeff S.QuickBooks should match your bank account if it’s cash method.

But I suppose there might be a kernel of that that you could adapt for your purposes since it's an issue that keeps coming up.

I can tell you how I account for these things but I am sure that my method is just one of several solutions that may fit your circumstances.First, repairs fix things that are broken.  

A technical question for those using electronic rent colletion methods -For instance if a tenant is late on rent, I assume the system emails them with a notice saying so.

I do not know how common the method told by @Ron Scribner and @Sean OToole are in other states.

I will test a variety of methods, but everyone seems to advocate the standard direct mail method. 

It's a public forum, choose to follow the advise of posters with great care.Most investors doing rent to own, L/O and contracts have followed old methods for decades, most IMO are behind the times and while they can read things in black and white in federal laws, they don't always understand the intent, even attorneys have trouble in some areas of financial regulations.

My point is that I would use a method other than the Zillow estimate to attempt to value the home.