Ask HN: Consultants and independent contractors, where do you find clients?

Pre-pandemic, I was able to network easily at conferences and meetups, but in the time since, I haven't found a good replacement. I'm a software engineer and former CTO, interested in both custom development and higher level questions of technical strategy and system design. Places like Upwork don't seem geared to this type of work (unless I'm mistaken). Is this kind of work now mostly handled by large consultancies that provide contractors, unless you have significant connections? How are you all networking and marketing yourselves in these unprecedented times?