It never ceases to amaze me how many marvellous ideas fantasy novelists have for magic. When I first started writing I only had a few basic ideas, but as the story grew so did the varieties of magic. I have tried not to have my sorcerers and wizards becoming increasingly strong but rather discovering new aspects of their power.
In a world peopled mainly by sorcerers, I have made my life complicated by creating each sorcerer with his or her unique set of powers. Many have very few powers while the stronger sorcerers have more choices to draw on. On the other hand, I have a group of woodfolk who do not think they possess any magic at all although, by the standards of other people, they do. Luckily for the demands on my organisational ability, woodfolk all possess the same powers as each other. In case you’re wondering, a wizards is a sorcerer who has trained as an apprentice under another wizard and is specialist in magical and healing knowledge so they can optimize the power that they possess.
Have you thought that a fantasy world is the same as a geometry? They both must have an internal consistency. Each has its own assumptions and rules within which all manifestations must exist.