With the risk of giving you a non-answer:

In my personal experience there’s no substitute to building relationships if you’re an individual or small company looking for contract/freelance work.

It starts slow, but when you’re doing good work and maintain relationships you‘ll be swimming in work eventually.

OP here. That's the answer I was gonna give... most of the freelancing work I did was via personal relationships.

Often personal relationships with companies that employed me in the past, or companies where ex-colleagues worked.

The only single time I did freelance work for anyone else was when my neighbour (a graphic designer) sent some work my way.