Describing the Unknown

[Amanita]

This might also fit into "world-building" but I think it is a matter of writing.
I'm reading "Mistborn" by Brandon Sanderson at the moment and all in all, I really like his magic system. But there's one problem. During the fight scenes I still have no real concept as to what the characters can do, what happens when they do and so on. I'm sure Sanderson explains it somewhere before but it still takes going back and rereading to really understand which makes following the fight scenes rather hard. And he's already being critisised for spending too much time explaining his magic system... (I don't think so, but I really like to read explanations for magic systems or I wouldn't be hanging around forums like this.
Writers dealing with fire balls, elves and vampires do not have this problem, these concepts already are familiar enough for everyone to have a clear picture in their mind but with the more original concepts we all like to see this becomes relevant.

If you're using fantastical elements which aren't familiar to the general public, how do you make these come alive? How do you allow the reader to come into the character's head and allow him to feel what the character is feeling?

[Greybeard]

I have something like this in my novel. Several characters experience strange powers that are unlike anything described elsewhere.

What I do is zero in on the five senses of the viewpoint character. What is she seeing or hearing? Does her skin tingle, or is there a temperature change? Does the air smell or taste different? Also, what is her emotional or psychological reaction?

Once the unknown is described in these terms I have a character assign it a name. So the next time that it occurs only the name is necessary to explain what took place or appeared.

[CicadaGrrl]

I try to work foreign elements such as world or magic as organically into the story as possible. The conversations, emotional upsets, destinations etc. tend to lend themselves towards a seamless introduction to a new landscape--inner and outer.

[Map the Dragon]

This might also fit into "world-building" but I think it is a matter of writing.
I'm reading "Mistborn" by Brandon Sanderson at the moment and all in all, I really like his magic system. But there's one problem. During the fight scenes I still have no real concept as to what the characters can do, what happens when they do and so on. I'm sure Sanderson explains it somewhere before but it still takes going back and rereading to really understand which makes following the fight scenes rather hard. And he's already being critisised for spending too much time explaining his magic system... (I don't think so, but I really like to read explanations for magic systems or I wouldn't be hanging around forums like this.

I would willingly take Sanderson's success along with the criticism.

I loved the Mistborn series and recommend it all the time. If you think that magic system is complicated, read his new 1000-page epic The Way of Kings - say goodbye to gravity altogether and mix in some other elements as 'magic-battle' twist, turn, flip, and utterly confuse you. For some reason, I just get it. I didn't have any problems with Mistborn - likewise for TWOK. And, I love long, complex fantasy reads. I can see why some might accuse him of being too complicated and all, but this is where I find the wonder. Sanderson's magical systems are more original than anything else I have ever read - or written for that matter.

We get so caught up in the conventions of our genre, that we forget, sometimes, to just let our imaginations go wild. The magic in Mistborn has a basis and explanation in the science of that world, with relationships to various metals and combinations. Once you get it, it's pretty cool - as the system then becomes more predictable and you understand the implication in his other novels of what having this or that metal might mean to a character.

Now, if you're inventing your own unique system of magic, you have some choices. One, would be to go along with the Sanderson mold and explain EVERYTHING and OFTEN. i took a much more generic and vague approach. In my novel, there is a new magic born to the world (acutally a couple) and I just let the characters weilding the power to experience these powers much like you or I would. What would happen if all of a sudden I randomly just got powers? I'd run the emotional gambit (fear, excitement, power, responsibility, control, etc.) I would experiment, testing my own limitations. I'd hide it or show it off, wield it or refuse it, and much more. I had some complex emotional scenes with one of my protagonists, Aulop. He becomes the possessor of certain abilities, and with no history or knowledge or support, has to deal with them.

I do make some allusions to old historical documents that border on mythology, but mostly just to help my readers along with the budding power. I don't explain the magic, I just show it being born - it was much more fun this way.

[Amanita]

Sanderson's magical systems are more original than anything else I have ever read - or written for that matter.

That I fully agree with. And as I've written above, I've liked most of it as well, but the magic got me confused at some times. This might also have been due to language problem though. I'm not familiar with all the alloy names in English and sometimes wasn't sure if something is a real metal or an invented one which made everything more complicated of course. And "pewter" doesn't even have a proper translation.
Some thing, I only found out through the internet, for example what the stuff Vin is forced to swallow actually is. More or less unwillingly I found out more than I wanted to about the future books, that's one reason why I'm unsure if I should read them. His take on religion isn't really to my taste, but I'm fond of the main characters and of the magic even if it might sound differently above.