Lately I have been finding that is the most common question I receive.
To start I do a fair amount of networking from friends, past co-workers, CEOS I have worked for and so on. This part is continuous and you can reasonably expect to be doing it for as long as you are working.
I advertise with a website and my vision to almost everyone, even though they may not be in the position to hire me, they may come across someone who is and remember that they met an enthusiastic contractor who they know could do the work. This will pay off long term as people will start contacting you.
Lay down a vision for yourself and for your services. Where do you see contracting taking you? What can you provide to companies? Do you want to grow into a team of contractors? Do you want to only contract alone? What kind of contracting will you focus on to start, and what kind will you do further down your road map? These questions will help you strive to your long term goals and help you be more targeted in your short term goals. When you get going, don't forget to take time, take one day off from work and dedicate it to reflect on these questions and re-paint the picture so that it stays up to date with you and your goals.
Target one customer at a time to start. If you can live off of one small contract job, do it and do it well. References and Quotes are everything to start. These will help you land new customers and will become proof points. It also grows your network by large margins!
Be patient, it is expected to take a long time and a lot of effort to grow a network. I have met and worked with people that have spent their whole lives building their networks where most of their work is still focusing on that network.
I found it helpful to find a friend or co-worker that shares in your vision and is willing to share the journey with you side by side. This has not only validated decisions but kept me from losing enthusiasm too.
A good many things have lined up for me so far. It has helped that I know a few people in the recruiting industry and I have been able to gain insight from them about jobs around the country and how they work with customers and what customers are looking for. The job I left also has provided some opportunities for work as a co-worker of mine and me were valuable to the company and they wanted more work from us post leaving. The other option is to of course join a starting firm that is just starting out and enjoy doing the contract work with them and for their customers. Maybe its 1099 work maybe its W2 work but remember that if you take this option, learn as much as you possibly can from them and when you are feeling confident, take it on yourself.