Using a "fast turn" instead of a "buy and hold" strategy regardless of the negative cash flow.
Our 1983-bought $117,000 San Diego property was in negative cash flow the entire time we paid the 15 year mortgage until the mortgage was paid off 9 years into the loan.
Now, that property spits out $1,400 per month in rental income and is worth about $400,000.
My only regret is that I did not "buy and hold" ten more just like it.