Publish steadily and gradually build an audience.
This is sadly out-of-date advice.
Once, publishers were patient enough, and had enough faith in readers, to keep bringing out an author's books until he built a readership. It does still happen, very rarely; the last writer I heard give this advice was Michael Connelly, and it worked for him. His publisher, Little, Brown, stuck by him, and they both got rich.
Very few members of the Class of Spring '77 found such loyal publishers (without writing a bestseller first time out, as Brooks did), though Chesbro and Jackson had long runs, and Townley, Zaroulis and Hall had medium-sized ones. (See the chart for more detail.) And publisher loyalty is crucial to this career strategy. If an author has to keep finding new publishers, as the majority of this group did, the intervals between publications lengthen, and hope of building an audience dwindles.