Keeping Them Posted
This is a recommendation from one who has sinned in this area but my transgressions do not diminish the importance of the topic:
Give updates to others on your projects.
By "others" I don't mean those who have no interest in the work. [I recall a co-worker many years ago who used to copy all of his associates on practically everything he did. If I had a royalty for every time a Delete button was pushed in that office, this post would be coming from Tahiti.]
Those who do have an interest, however, appreciate a brief status report even if there is no change in the status. It tells them that neither they nor the project have been forgotten and thus is quietly reassuring. In the absence of such reports, it is easy for the person to conjure up all sorts of negative images that produce one irksome thought: They don't count.
Although that may be far from your true feelings, you still need to announce that matters are in hand in order to banish the fear that they might be in for an unpleasant surprise. At a minimum, this should be done once a week. I've long recommended to clients that they write a weekly Significant Action Report so they can, via a one or two page memo, bring their boss up to speed on their projects. It can also help to send single topic updates to associates or clients on a weekly basis.
These updates reassure them and, let's be frank, help to keep us on track so we don't forget about their concerns.