Good investments can be made in any market provided one has excellent local market knowledge. 

Once I have an idea on the MTR pricing then I go into an Excel Spreadsheet I created.

The art is to increase the rent without running off GOOD tenants (very important, if the tenants aren't ideal tenants then non-renewing becomes the default option).

Perhaps that means pursuing art, consulting, teaching, etc. 

LOLI have my own Excel sheet calculating all of these, because none of these are not unpredictable.

They are excellent and understand the process. 

New York has outstanding judgment collection laws that allow for levies on accounts and payDaniels, Norelli, Scully & Cecere are excellent

Wow, there are some EXCELLENT posts on here, I have voted for a couple of them. 

If you are looking for ways to track/calculate principal and interest payments, you can use loan amortization excel template, plug in the principal amount, loan date, interest rate, and the number of years to pay and it will show you the monthly breakdown/details you need to track the loan.

Daniel provided excellent insight, and just to add to it.