I have been doing database management work for 15y+. My preference is strategies that take least resources to implement: time and money. My website is: red9.com Ask any questions and I will try to answer!
I spent 10 years building a digital agency so I've got some experience with client acquisition.
The short answer is - client work leads to more work. One way to start the pipeline going is to pick up small jobs from any number of project sites and to build from there. Chances are if I have a small project I'm working on, there's more work to be had. Most big engagements start with a small project.
If you give me some ideas of what you've tried in the past perhaps I can refine the approach a bit. Happy to help.
It's difficult to find companies that need your service. I would suggest flipping that question to ask, "How to I attract companies that need my services?". Having an inbound marketing strategy, to attract qualified leads to your website is a great way to increase your clientele.