They say hindsight is 20/20. The biggest mistake I made when I got into the photo/studio business was spending way to much time and effort on being good at "the craft". What I learned the hard way is that that is what hobbyists do. It is also why IMO many hobbyists do technically better photography that many pros.
What pros who are serious about making a living the business of photography do (actually what people in any business that requires active sales does) is spend most of their time and effort schmoozing/doing marketing/finding new work. They are almost always in marketing and sales mode.
By most here I mean somewhere close to 80%, number comes from business coaches not me. When I applied this rule I was successful, when I didn't I wasn't.
Successful photographers/sales people will spend 7-8 hours a day talking with clients, calling galleries, going to openings, wedding shows, asking for referrals, following up leads, blah, blah, blah. The other 2-3 hours a day would be spent doing the books, the banking, the bills, and getting in a bit of shooting and printing.
So for a guy that goes out for a weekend and spends say 16 hours traipsing around shooting landscapes then spends another 16 hours the next weekend making some really nice prints it is not unreasonable to think or expect that is should take another 128 hours of work (the next 8 weekends at 16 hours per weekend) marketing to actually get those prints sold.