Giving referrals is a habit you can develop. Create reminders for yourself in your office so when you're on the phone with people, you are listening for clues. People usually don't come right out and tell you they are looking for a referral unless it's an immediate need. That doesn't happen often enough to make giving referrals effective for you until you've developed your image as a resource. The Chamber office gets calls on a regular basis because it is part of our organization's reputation and we work to cultivate it.
Here's a flip side of giving referrals. You want to be careful because people don't want your advice. Even when they seem to be asking for advice, very often they are just complaining. When you start trying to give referrals, put it out there very casually and see if the other person starts asking more questions. If they ignore your helpful statement, then they aren't interested. Pushing a solution on them is going to make everyone uncomfortable.
I've received referrals like this. Where someone tells me that they've informed someone else they should join the Chamber. I call that person and it turns out that's exactly what happened - they were told, they didn't ask for a call from me. I end up talking to someone who wasn't really interested but they were too polite to tell their friend, "No."
Don't let this stop you from giving referrals to your friends or to me at the Chamber. If you put your resources out there, people are going to need what you and your contacts have to offer.