Magic 101 (lol)
Evocation-instantaneous spells often of the kaboom variety. Classic fireball throwing image
Water-control of water and other liquids(acid for example) however also encapsulates entropy, the natural decay of matter too.
Fire-Boom! control of fire but also heat, can be used to create ice by removing heat from an area.
Earth-controlling the ground beneath peoples feet, but also contains gravity and magnetism. Also electricity if you're talking geo-electricity.
Air-controlling the wind and oxygen. Big gusts of air or, if you're feeling mean, the complete removal of oxygen from a zone. Also movement magic such as flight or speed, although these are risky as it can lead to crashing and death.
Spirit-two sides to spirit. Raw physical for e.g. telekinesis and huge barriers are one side to it, however there is also the subtler side which includes mind magic, creating light and veils(like invisibility cloaks)
Thaumatury-ritual magic, often requires set up(drawing chalk circle as a minimum) and time to complete. Rarely if ever used in combat. You also must have a symbolic link to what you want to manipulate(think voodoo dolls). True names, blood, hair, pictures and other things can all be used as symbolic links.
Technical specialties-many wardens choose to specialise in these fields, having a great degree of freedom in each one.
Divination-finding stuff or people, using the symbolic link to find them. Can also be used to divine injuries on a personal level
Conjuration-used to create physical matter from ectoplasm, the substance of the Never Never. You can make pretty much anything but the larger and more complex it is the more energy and time it will require. I quite liked using this to make gold to scam people with.#
Summoning and binding-summoning entities from the Never Never might be difficult as in this story we are actually in the Never Never. However this could be used to call beings to our side and then bind them to our wills. However there is not a being alive that likes being bound, often safer to summon and then bargain with for service. Also a circle to contain them when they arrive is never a bad idea, more likely to listen instead of biting faces off.
Wards-often around locations to create magical fortresses, however temporary ones can be created one scene to bottleneck enemies as an example. Alongside this you can create wards upon your person designed to trigger in specific circumstances. I once created one to stop me from dying if I fell form a great height.
Transportation and worldwalking-magic to get you from one place to another is include under this. Including the ability to open portals between places in the Never Never. Given the nature of our story it might be an idea for at least one of us to possess this power.
Crafting-think alchemy but also making enchanted items that you can use in combat to prevent you having to exhaust yourself with magic. I once created a walking stick that avoid static electricity, which could then be used like a taser.
Transformation and disruption-creating permanent changes in people. This can often include death spells, which in the Dresden Files are illegal. also turning people into other things and cursing them. If you're looking for a less fatal use, we once had a character that produced temporary and beneficial boosts for teammates.
Thematic Thaumaturgy-These are themes that will often embrace several of the technical fields above.
Biomancy-magic worked upon the body. Healing magic can fall under this specialisation, short-term supercharging as mentioned above, divining if someone is injured, also creating wards that use the natural world(wall of thorns anyone)
Diablomancy-as mentioned above this is magic involving demons. Wardens are generally against this however you could use it to divine the presence of demons(or learn if someone is possessed) create wards that are specifically useful against demons and, of course, Summoning and Binding them.
Ectomancy-The magic of ghosts, you can use this to commune with the dead. Except under special circumstances ghosts are usually invisible, not to an ectomancer. They can divine if spirits are near, or have gone this way, ward a room to keep them out(or in) summoning them and binding them to a task, and crafting items to protect from them.
Entropomancy-cursing pure and simple. This is the magic you use to bring everything from bad luck, to out and out death on people. If you're feeling nice you can divine if someone is cursed, and transform them to get rid of the curse. Create wards that curse people that go through them, or wards that remove curses.
Necromancy-messing with the dead is breaking one of the laws of magic, strictly forbidden and wardens hate it. If you were looking for a work around this technically only applies to human dead bodies. You could summon up an army of dead rats or maybe a dead raven to spy. I could see lost wardens justifying it's use to survive.
Photomancy-manipulating light. You can create long term invisibility with this kind of magic, but also illusions so realistic that your own mother wouldn't know the difference. Wards that disguise rather than block access are examples, making a place invisible too. You could bring in conjuration to give your illusions solidity.
Psychomancy-messing with the mind. Breaks another law of magic, but once again i could see desperate wardens turning to it. Could use divination to sense active minds nearby(without invading them) also supercharging your own mind(to keep awake all night or increase your reaction speed. You can also bring emotions into this, wards that induce terrifying fear in people for example, scaring them away.
And breathe
The game does stress that you could create your own them. However be realistic, don't create a theme that gives you access to everything, that would be silly.
That's the large majority although there are sections on sponsored magic that I could include if you want. Think of sponsored magic as a power boost with a lot of strings attached. I cannot stress enough how many strings there are.
On the subject of worlbuilding I kind of like the idea of a metropolis that runs on magic rather than technology(as magic breaks technology) maybe a chance for us to pick up some new skills and maybe find a way home too.
That's it from me.