I think there is a lot of good information in this entire thread. I would add, having a good website helps. It all has to somehow happen at once. You have to develop a solid reputation, but you have to have customers for that to happen. Websites that are well done, can help with that. Its an intro to potential customers that are looking for work. People look for different things, obviously the type of work you do, legitimacy in business and pictures help. They want to see what you have done, even if its not the exact work they are looking to have done. Once you get the site built, make sure it is optimized to show up in your area on a web search.
Some other points I would make. I think you need to find a niche, what that is depends on what is going on in your area and what your skill set is. I would say that my area is crazy, everyone is moving here from other States and it is busy, both residential and commercial. As busy as it is here, if I had what you had for equipment, doing what your trying to do, I would probably starve too. I think you need to find a direction that makes sense for the area you live in. Then promote it, and EXCEL at it. Once this is done, find builders and GC's and talk to them. This is really critical to long term success as has been mentioned. I will say this, before you show up at ACME construction peddling your work. You better competent at what you want to do, know what your talking about. That saying "you only have one chance to make a first impression" couldn't be more true in this line of work. Also important, is being someone that people like having around a jobsite your attitude and personality almost as important as how good you are. Emotional intelligence is critical. When your wrong..and you will be at times, admit it and make it right. I have lost a lot money keeping my word, but 27 years later I am still here. The test of a contractor isn't when things are going well, but what happens when there not. Contracting is really about navigating issues, you need to be successful at that skill as well.