"My clients will call if they need me."
You can do this during the initial stages of engagement, but even with established clients, there is nothing wrong with inquiring about the preferred frequency of contact. You may find that your client would like a regular update even if there aren’t any new developments. That’s good news for you. Regular check-ins will not only deepen the relationship, it will increase the likelihood of referrals.
Once you have established frequency, inquire into modality. Some people are more responsive by phone than email. Others prefer text if the matter is urgent. Let them indicate their preference so you can adapt accordingly.
As you go through this process, you will find that ninety percent of your clients are comfortable with whatever protocols you have put in place. This exercise will help you retain the disenchanted ten percent. And the very act of asking demonstrates to all of your clients that you place a high level of importance on service and communication.