Examples of questions:
Is there some magic move with the fingers you have to do? Perhaps the whole body needs to move in some weird way?
Do you have to say some magic words? Which language? Remember, lore-wise daedric is not a language. Just a different kind of letters. (atleast according to http://www.imperial-library.info/daedric/, trust them if you want)
Is concentration and thinking a part of it or can you just walk in a room and light people to flames without really thinking very much?
Do some spells require rituals to be made (like the gate to Camorans paradise which Martin is conjuring up) or do ALL spells need rituals? Or is rituals some time-consuming nonsense?
What about scrolls? How do they work? Should you just speak the words while holding the paper and then the spell should come to you? Or is it more of a helping hand? How has the spell "got in" to the scroll?
Think a little (or not) about this and decide what you think is plausible/realistic/funny!
You do not need to answer all of these questions, just see them as help to get your mind going in the right way.