I tackle this sideways by going to Meetup or Eventbrite. Specifically I go to meetups and events that potential buyers go to and let them know what I do (I don’t try to sell my services on first contact). It takes some pruning but after a while my preferred clients are the ones I keep in contact with and we start working. I get less work through this than just by referral though.
Depending on your living situation and time available I’d recommend trying to establish your own identity so you don’t have to go through a marketplace for contract work. Instead you’ll have the contract work come to you and not filtered through a middleman that would take a cut out of your work. I would never recommend someone go through fiverr, Upwork or these other marketplaces unless they were just moonlighting.
Depending on your living situation and time available I’d recommend trying to establish your own identity so you don’t have to go through a marketplace for contract work. Instead you’ll have the contract work come to you and not filtered through a middleman that would take a cut out of your work. I would never recommend someone go through fiverr, Upwork or these other marketplaces unless they were just moonlighting.