A good slogan to use to understand Cash Flow is:
"The Investment doesn't cash flow.... but the INVESTOR does."
This slogan merely means you can put down ZERO and the Investment will be NEGATIVE but if you buy it without financing it, you will Cash Flow.
You make the Investment Cash Flow.
Also, Cash Flow can be a distraction from much bigger problems.
Buying a Property that you cash flow in a DEPRECIATING Local Market is a set up for failure.
Take Detroit during the decades before it went bankrupt.
You may have bought a Cash Flowing property decades before, but the writing on the wall was that Detroit was going to depreciate when the Domestic Auto Industry was a decades long slow train wreck.
Detroit, at that time, was 90% dependent on Domestic Auto.
There are 2 rules that I follow:
1) ALWAYS buy in Appreciating Markets with a horizon of at least 10 years
2) You (notice, I said YOU) SHOULD Make the Investment at least break even if not some positive cash flow
If you are in an Appreciating Market, your Cash Flow will grow.
For instance, I am in Brooklyn, NY and my first investment was in 1998.
My rents went up over 350% (from $1k for a typical 2 Bedroom apt to $3.5k today) over the 26 years.
Not only do I cash flow from the Rental Price Appreciation but soon my Mortgage will be paid off by the tenants.
The Cash flow will be HUUUGE in about 2 years from now.
Many Investors here seem to not understand that Appreciation is BOTH the Investment's Value and the Rental Price Appreciation. I don't think you can get Appreciation in Value without getting Rental Price Appreciation.
Go after the gold and get BOTH Value and Rental Price Apprecation!
Anything else is just silver.