Fantasy author Brandon Sanderson has actually written a few interesting essays on how to design magic systems. Sanderson’s laws are generally summarized as: 1) An author’s ability to solve conflict with magic is DIRECTLY PROPORTIONAL to how well the reader understands said magic. 2) The limitations of a magic system should be greater than the powers of said magic system, and 3) Expand what you already have before you add something new. Thought you’d find this interesting!

Thank you! I find different magical systems fascinating.