As you progress along your career path and publish more, you’ll begin to gain a reputation in your niche. You may even build a decent following along the way.
If you’re interested, you can consider branching out and playing with different projects. For example, you may want to freelance for other websites. If that’s the path you’re pursuing, I recommend reading this post by Nick LeRoy. While it’s specifically about SEO freelancing, most of the principles can be applied to any form of freelancing.
There are other monetization opportunities too, besides freelancing. Ideas include: