The most important thing is probably having that network in the first place, not just to offer referrals but to get good gigs yourself.
I know a few very experienced people who have looked into contracting or freelancing over the past year either for the first time or for the first round in many years. They have good skills and the aptitude to pick up whatever else they need, but without the broad network that comes with years of doing short term gigs, they've found the market very tough to break into. I doubt they would recognise the talk of a seller's market and ever-increasing rates that we see on sites like HN!
If you don't have that network and people actively seeking you out, you get stuck with looking via agencies (= ghosted often if you don't already have exactly the right buzzwords) or the online marketplaces (= low rates, poor quality clients and high risk of problems with the marketplace itself). And even if you do, I've seen more than one person whose whole network basically all fell apart around the same time because whole industries were hit by COVID.
Today even more than usual, it is about who you know as much as what you know.