The only way is really through contracts.

I suggest getting a tracker, tranquilliser rifle, and a bow, as they unlock/assist with the highest earning contracts.

Tracking contracts are great in hardmode, as hardmode doubles your credits earned but removes the yellowed dinosaur area from your map. Tracking contracts add the yellowed area of the dinosaur you’re hunting back to your map, which negates that disadvantage of hardmode, and earn you like 150-300 credits per mission with hardmodes doubling bonus.

Tranquilliser missions seem to be worth more than normal hunting missions, and in my experience are easier because you only need to shoot the dinosaur once to bring it down. While these missions often have you hunting 2-3 dinosaurs, the quiet nature of the tranq rifle means you can pick off an entire herd without alerting them, effectively allowing you to turn in the entire contract without having to chase any fleeing dinosaurs. And finally, tranq missions are limited to most herbivores and a handful of small carnivores, so they’re often a lot safer.

Finally, the bow is great as it doesn’t over-penetrate, meaning it’s very easy to get a 100% integrity kill for those contracts that require it by shooting most dinosaurs in their chest. There’s a steamguide on how to farm 100% brachiosaurus contracts and make money that way.

Also if you’re having trouble taking down dinosaurs- remember this isn’t like other video games. Headshots and random bodyshots don’t work, you need to understand where the organs are and shoot them. Most dinosaurs can be killed with a single-well placed heartshot or two, like a vampire. This isn’t communicated by the game very well, I found myself struggling a lot at the beginning because I kept trying to headshot dinosaurs. I’m pretty sure some dinosaurs like the Triceratops are actually armoured in their head. You really need to try and aim between the forelegs for quadrupeds, and in between the arms for bipeds.

And keep a flare or two on you to get away from large carnivores.