One resource I like is the Youtube channel Just in Time Worlds, who I would say specialises in epic fantasy / high fantasy worldbuilding.
There are so many videos on specific topics such as magic systems, geography, politics etc. She is also very thorough with explaining everything, and pulls out specific points and tips I haven't really seen anywhere else before.
I used these videos a lot when worldbuilding the culture and history of my fantasy novel. That channel is so underrated imo, I hope this helps other people too!