Ask HN: How do I find ML consulting clients?

I want to make the move from in-house machine learning work to working as a consultant. I have a good grasp of how much I should charge, but I'm at a loss for how to find clients. My expertise is in medical computer vision but I have experience working with many other data types. Should I limit myself to one small niche?

What is a good way to start finding clients? I have attempted to make a list of potential companies from LinkedIn, but it also occurs to me that companies I find through LinkedIn are more likely to already have a sizeable ML/AI team. That in turn means it is less likely they have a need to contract some of their ML work.