It took me a while to make the jump. I started by earning my dues working too hard for two little pay with some small-time clients early on. I built up a decent portfolio that I could show off and started using that to market myself. I sent it as a link to adds I saw on craigslist. I did a couple projects on spec that I worked really really hard on and sent links to the company offering it for free. You'd think that would be a huge risk, and frankly, it is. But in fact, both of the times I did it, I got major clients. Kept building myself from there.
Yes I did. It was very hard work. I combed through hundreds of adds, sent custom replies to several dozen of the most promising and made it clear that I was offering high quality, with the unstated caveat that I was not offering the lowest price. I replied only to adds local to Boston (where I live) and said that I would be happy to come to their location at their convenience. When I did in person interview I dressed very well, and read up extensively on their companies beforehand. I did not even entertain anyone that seemed like a cheapskate or wanted to offer equity.
Advice sometimes isn't worth the (web) paper it's printed on.
But take a long, hard look at the clients you are most successful with. Identify the larger market that fits that criteria. Then, how are you going to compete with the people already in that space?
I think of it the same whether doing a startup, consulting, or pivoting a business.