Worldbuilding

Not a fan of when there's one magic system and seemingly everyone in the world is on the same page about it. Even in science you have conflicting theories to explain certain things - with magic, where half the shit you do is seemingly random and the results you see are based on vibes, practically every person wielding it should have a completely different understanding of what they're doing and why it works. That should be the reason why it's so hard to pass from teacher to student - I could teach you to do the same things I do, and speak the same incantations, but that doesn't mean it will work for you the way it does for me, because it's magic and it's inherently illogical.

I don't know how to articulate this properly but I don't like when magic feels too much like its own thing separate from everything else or when it feels too much like a fully itemized system. It makes it feel like it's this entirely self-contained model bolted onto an otherwise normal world. This is something that's really more in games than anywhere else for very obvious reasons, but when magic is fairly common and magic is in the form of discrete known spells that always work the exact same way every time no matter who's doing it makes it feel really artificial and gamey in the same way that character levels being known in-universe would be.

I really like when you have things like every fireball or magic missile or whatever being slightly different the way that every handicraft is slightly different, even if it's the same "spell". I really like when there are outside forces that influence magic, like the planets are aligned correctly so everyone's magic is supercharged but unstable, or you're in a sacred grove so your spells do xyz things different, stuff like like that. Things that make magic feel like it's some supernatural force that you're tapping into instead of pressing a button .