Network with people directly via physical world and web meetings. It requires some time and monetary investment (building relationships and traveling to conferences), but once you have build a network of even 4 or 5 people who value your skills out of which at least one is offering you a gig, you are all set. You can now use this network to vouch for your skills, ethics, and expertise to get more gigs.

Sure, Upwork is much easier than this but with this ease comes this huge risk of your livelihood disappearing into thin air at the whims and fancies of Upwork.