My start in freelancing was forced. I was laid off as part of a merger for lack of face time (fully remote, while others showed up in office so naturally they were chosen over me). It was really tough. I lived in an expensive area all of a sudden without an income. I guess the reason I did not go applying for jobs was just the sour taste that the layoff left. I felt angry, not at the company, but at myself for letting others dictate my life.
I started on Upwork. It was a bitch. Upwork is known for low quality, but I didn't have any choice. I just tried doing as best as I could for everyone I dealt with and that seemed to manifest into a 100% rating, which led to even more contacts. At one point some of the clients weren't so terrible. I think the first year I did 40k, much much lower than the salary I had, but it was enough to pay the bills. I also moved to a much more affordable area so it helped.
Having 100% rating on upwork lead to agency work. Agencies are great, if you do good work they often have a steady workload for you. You know what comes and when and can schedule more time to work on other projects, thus upping your income. If you are a developer working with an agency, this can be very rewarding if your charge your worth. I am a designer and our industry naturally caps what people think I am worth. It sucks.
At one point I was doing well enough that new clients I was taking on were willing to pay per project. It was super hard and scary, but I said bye to agency work except for 1 agency where I befriended the CEO. Per project work was really nice, but I learned quickly that if you can't sell your value (which I couldn't at the time as a "designer" and just lacked experience in this area), it can be difficult to close larger quote projects. People are just scared of large numbers. Tell someone they should pay you 50k and they run away (I am sure that other's experience may differ and people don't mind paying them that sum). I tried a bunch of things, price anchoring, huge fancy proposals.. yada yada. What happened is that I was getting burned out on huge fancy proposals and not getting anything out of them and that was the breaking point. I figured, I am done with proposals, from now on I get people on the phone, talk to them, and if they don't agree at the end of the call then I won't put any more effort. THIS WORKED.
Now the process is simple: Schedule a call, we talk, I ask you about your BUSINESS problem and offer you a business solution. No talk of design. No talk of development. What is it that is costing you money or not making you money? Let's change that.
As far as new work it's 100% referrals at the moment. However, I know that this can't last forever and at some point I will burn out (I already feel this after 3 years). My goal is a product or a product-service (have someone else do the work I offer at a reduced scope for a cheaper price). I have read about several people here on HN doing this and making a killing (by my definition). This is what I look forward to next, but it has not been easy. As a side note: if anyone is running a product service or a SaaS and started in a similar fashion, I'd love to hear from you!