I agree, while this isn't the only way to do magic by any means, I think it is still a neat list. But people should remain flexible in their ideas of magic - for instance, a group of Rpers and I once accidentally made up a magic called soul-binding where you use souls for different spells. This isn't that innovative when you consider the multiple shonen stories that I'm sure have this as the plot, but it was nevertheless fun to Rp. Plus, when one character was killed off, we were able to keep him around as a character because one of my characters "collected" him! So the possibilities are endless.