1. Not Knowing the Market Numbers
Knowing your market is as important as any other factor in real estate investing. This means having a neighborhood by neighborhood analysis of the supply curve and average days on market. Both of these data formulas can be found through the assitance of a real estate broker using the MLS.
2. Mistaken Value
Most new investors use Zillow, e-appraisal, or Trulia (or even worse, an average of the three) for determining the value of a property. This is fatal – learn to do a “comparable sales” analysis.
Get your own data, too. Relying on the listing broker to give you comps for properties is like asking the barber, “How’s the haircut”. Learn to find your own comps using public data websites like Trulia.com.