To sell a place, interview 3 or 4 agents at your place (which should be in impeccable, showable condition for the interviews: spotless, freshly painted, with 2/3 of the junk in storage elsewhere.) Ask them each to run comps and give you a listing price. Begin to negotiate with them on their commission (which will depend on the location and the market). When you get each agent's offer, decide after a phone conversation with the one you liked the best. Don't choose on their suggested listing price alone, but rather on their marketing plan, how well you get along with them, and your conversations with their references. (Choose the 3 or 4 agents to invite for interviews by visiting open houses in your neighborhood and chatting with the agents, to get a sense of who is professional, reliable, courteous, and compatible. And, of course, ask for recommendations from trusted friends.)

To buy a place, sign a contract with a buyer's agent who represents you, and never the seller.

My sister, a broker, gave me this advice, and it has stood me on good stead for the various houses I've bought and sold.