Some things include - Letter type – handwritten letter in the mail (“Hey, I’m Julius and I want to buy your property, please call me at [number]”; more formal, typed letter, any other variations people think I should include- Address of property- Address of owner- Date sent (anybody know how often I should send?)

Take the time to work out: WHY the variations? 

NOI/PP does little for you in itself there, but can be a tool like a variation of tax assessed value and sold comps to try and find true FMV.  

Once you get a mortgage your payments are set, they change it only for variations in your escrow account.

Cookie cutter units vs. lots of unit variation is preferred to make renovation work easy to multiply and duplicate.

Obviously it's important to understand what income taxes will do to your investment income in order to pick the best investment(s).I agree that the way Dan does it IS the common understanding of "cash flow" when working out whether a "deal" is to be had or not ie. the tax implications are a separate, later consideration.Yes, perhaps your newly defined "cash flow" variations are a bit "too nuanced" (for me)!

The equity multiplier is a variation of the debt ratio, and its definition of debt financing includes all liabilities."

Every state has some variation of how it happens if it happens at all. 

There is some variation from town to town with code officers.

. - There are some variations to that.