Be responsive! Answer requests and messages promptly and thoroughly.

Respect the caller's time! I always send a pre-call questionnaire in the message field. I won't take the call until I receive answers to the questionnaire. That way I have my basics answered before the meter starts running. No phone time is wasted on getting-to-know-you questions: just dive right in to the heavy stuff. This saves you time and it saves them money.

Be honest! It's great to be labeled an "expert," but if you try to oversell yourself, it can only come back and bite you. Admit your areas of inexperience.

Put yourself in their shoes. Ultimately, the caller wants to feel comfortable and secure in their area. They're looking to you for help. If you can go the extra mile for them, that only helps them all the more. Refer them to other experts or industry professionals. Provide links to reading material and resources. Offer to follow-up a week or month after the call (and then make sure you do it!) to check in on them. Etc. Be more than a phone call. Be their help.