After a meeting I used to send a recap email: what we looked at, what we found, and what we agreed it might be worth. It probably got read once and sank under everything else in their inbox. So I gave each person their own private page. It starts as the summary of our first conversation. If we agree on what a problem is worth, those numbers go on it, labeled as potentials we agreed on together, not forecasts.
If we start working together, it's set up to show the next step and who owes it. There's no login, and the page isn't public. I build it from the notes I already keep, so there's no second copy to maintain by hand.
At the bottom of the page each person chooses how often they hear from me: check back in two weeks, check back in four, or stop. Stopping is a fine answer. I'd rather know than keep guessing.
If your customers wait on you for updates, where would they look first? If the answer is their inbox, that might be worth fixing and I can help.