There are 100s of things! It's a business endeavor...it's not just site visits, moving soil, fine tuning edges and making routing decisions in the field. Wish it were, but it's not.
At our small consultancy we have a vast library (and not just pretty books with great writing about GCA...there are also a century worth of plant, agronomic and landscaping references, fence detail books, architectural standards and civil engineering text books); an archive of more than 7,000 plans and aerials dating back to the 1940s (from Jack Snyder and his work, then mine c.1980s); bookkeeping; and a host of other files, records, and "to do" stacks.
In between all this we answer calls, talk with people about potential projects, create concept plans, attend symposiums (ASGCA, USGA, etc.), and tend to the wonderful clients and clubs who have trusted us with remaining as "their GCA".