the key is to ask copiousness of open ended questions of either the seller or his agent and to not accept a simple "yes" or "no" answer. if you ask an open ended question and get a yes/no answer, your direct reaction should be to follow up with additional open ended questions! perceptibly, if you keep getting yes/no's to your questions, it may be time to find a more supportive and solemn seller.
some of the leading questions smart real estate investors use include:
• what can you tell me about this portion of property?
• what makes this particular property a good investment?
• what is it like trade with the city?
• tell me about your tenants … neighbors … city, etc.
• what can you do to help me get into this property?
• what financing are you willing to carry?
• what are your neighbors like? or "how easy are the adjacent property owners to deal with?
• how speedily do you need to close? why?
• why are you selling the property … now?
• what is the existing financing? how can it be assumed?
• what are the down payment requirements?