If you want to avoid having to compete with literally everyone Upwork, you have to think like a consultant instead of an employee. If you can take responsibility for the success of the project, that's noteworthy and you'll stand out. This can be how you get your referral system going.

To jumpstart that, you have to build your network. If you are still in university, that's a great position to be in, since you don't have to make money immediately (which is the best negotiation position).

Do things in public that demonstrate competence. For a dev this could include speaking at meetups, contributing to open source, answering questions in tech Slacks or on Hacker News, etc. Meet people and talk to them. Universities have all sorts of ways to do this. Do whatever you are most comfortable doing to meet people.

Stay in touch with the people you meet over email and make known your services without being obnoxious. This will all increase your "luck surface area" - participating in Hacker News has made you known to, for example, me, and anyone else who reads this. The more you do in public, the more people you meet, the more likely you are to find good gigs.

Happy to chat about this more if you have any more specific questions, as it's a topic I've had great interest in as a freelancer myself. Cheers, and best of luck in your freelance quest!