As a realtor the greatest tool that I have in learning what a client wants is communication and furthermore, it is ON-GOING communication.  Often times my clients think they know what they want and then their wants and needs often conflict and change throughout the process (on both the buyer and seller side).  It is vital that I ask questions and pay attention to the answers I get and the comments that I receive and pay particular attention to LACK of comments because sometimes, quite frankly they get shell shocked and don't want to admit that they actually didn't know. Documenting thier wants and needs is also imperative.  I take copiuos notes and then make sure I transfer them into my CRM and also in any search tools that i have set up for them as soon as possible so I don't waste any time in helping them achieve their real estate goals.