Ryan:
That is a great question although I'm not sure how many responses you'll get, nor how many of those will be entirely forthcoming.
When I worked for Pete Dye, all he did when he wanted work was to answer the phone [a lot of the time he didn't even bother to answer it]. His philosophy was that if somebody REALLY wanted him to do their course, they'd keep calling!
With such a great mentor, I did not know the first thing about business development when I went out on my own. Luckily, I had made a huge number of contacts back in the years I was traveling around to see all the great courses of the world, and those contacts provided most of the references for my first five or ten jobs. Then we got to build Pacific Dunes, and the phone has been ringing pretty steadily ever since. [I do pay someone to answer it when I'm traveling.]
Interestingly, one of the few courses which I ever pursued before being contacted about it was Pacific Dunes ... three friends of mine knew that Mike Keiser had purchased the property and suggested I contact him, and one of those early contacts, Bill Shean, provided a formal introduction. Generally, there is little point in pursuing a job unless the client already has some interest in you or you have an inside contact ... my lifetime batting average on winning RFP jobs is 0-for-life.
Some designers have a full-time sales and marketing guy, but most do it themselves because they can't afford to pay somebody that much. I'm just too cheap to do it, plus I worry that a good salesman would easily sign us up for more work than I'm comfortable trying to do in a year. So, I probably spend 25% of my time in the office (after taking out the 150+ days on the road) following up on potential new projects and otherwise keeping my name in the public eye. Or maybe 40% if you count Golf Club Atlas as a marketing vehicle!