33 Guidelines to investing in real estate...............

Guideline #11:  Good management makes good investments.

Real estate is not a passive investment.  Successful investments require steady and competent management.  A few trademarks of good management:  proper screening of tenants, keeping occupancy levels high, making sure the rental rates remain market appropriate over time, taking care of day-to-day maintenance, anticipating - and budgeting for - capital improvements, anticipating and solving problems, communicating sooner rather than later, and not letting issues fester.

It is not difficult.  It does require discipline and effort.  It is important.