First, tell them who a good referral is…maybe they should send you anyone with a housing question. Maybe they should send you people looking for rental properties or other investment opportunities because of your expertise in that market segment. Maybe it is someone looking in a specific location that you know well. Maybe if someone is looking out of state and you can help them get connected with an agent because of your or your company's extensive referral network. Next, teach them what information you would need…a name, a phone number, an email and a little background would be perfect. Then, tell them how they can provide the information to you and make it easy. And be sure to reinforce the referral with a thank you of some sort. You want to encourage the action of referring whether a sale happens or not. Finally, never appear too busy to help or your referrals will go to someone else.