I haven't really made a conworld yet, but if I do, there are some things I've thought about including. In fact, I've even thought about how magic could work. This thought popped into my head one day and I'm honestly not sure where it came from. It's not even a full magic system, just one small element that could set it apart from others. I'll try to explain it as best as I can.
So, the source of all magic would be the planet, and mages can tap into the planet's natural magic source to cast their own magic. But to use it, some part of your body directly has to be touching the ground, or another natural material, like a tree. It can be any body part, as long as a barrier like clothing doesn't get in between the source and the receiver. Different kinds of magic expend different magical energies from the planet. Like, casting a fireball spell would cool down the planet slightly, summoning a tornado would make the wind die down a bit, building a wall of water would drain a little from the ocean, freezing someone would take a bit of ice from the poles, etc. This all would lead to the eventual demise of the planet, since after so long, the wind would not blow at all, the planet would be cooled to dangerously low temperatures, there would be no water left, all the ice and snow would be gone, etc.
Again, this is just a random idea that I came up with, but it could lead to an interesting worldbuilding situation where magic slowly gets drained from the environment over thousands of years, starting with a prosperous society where magic abounds but leading to a post-apocalyptic scenario where the last humans are trying to survive on a planet where everything is terrible.
I am Thethat, ancient recordkeeper and etymologist of the Sajem Tan tribe, as well as the foremost satirical poet.
Duhden duhden duhdenfeh keh duhden duhden: Distracted pasta is unproductive and distracts pasta.