* General comparison: "The mountain lion is more dangerous than the bobcat."
* Escalating risk: "The situation became more dangerous as the storm intensified."
* Relative to another option: "Taking the shortcut through the woods is more dangerous than staying on the paved road."
* Emphasis on potential harm: "The chemicals in this lab are more dangerous than we initially thought."
* Comparison of activities: "Skydiving is more dangerous than bungee jumping."
The best way to use "more dangerous" depends on the specific situation and the meaning you want to convey.