I can only pick one?

Personally, I think an entire class devoted soley to teaching "how to teach grammar" would be helpful. I keep going back to grade school and try understand how I came to understand these concepts. I vaguely remember a monster that would eat part of a word and leave an apostrophe...which is why we have contractions.
That's the extent of my memories.
I usually feel fairly confident in explaining things; I think I probably use too many analogies, but as long as the writer is understanding the rule, right?
I like what Brianna was saying about evesdropping in on sessions. I do this all the time! I think the best way for us to learn is just to keep observing others' teaching methods. Actually, this reminds me of a Murraylicious situation. A group of tutors still learning how to be tutors, learning through the observation of fellow tutors. Hmm....
The class has helped me a lot. Fellow tutors have helped me a lot. I feel spoiled by the endless techniques to explain grammatical prinicples, so I shouldn't be complaining! I guess I will say that the grammatical rule that I have the most difficult time explaining would be prepositions. I am never exactly sure why you use one over the other, you just do. But in Ritter's essay, she says that when working with ESL students you can just give them the correct preposition.
So...I don't really have to attempt to explain it anymore. How convenient.