One thing that always troubles me is that many students tend to want to rush to draw procedural generalizations before they reach a solid conceptual understanding. What this means is that in two weeks, when I'm not standing in front of them, they do not remember how to properly apply the rules and cannot even retrieve the relevant concepts to re-engineer those rules! argh.
This year, for teaching exponents, I am going to sloooooooow them down to try to avoid that.
Here is my attempt at pulling together a worksheet on exponents (which, granted, isn't the most exciting of topics). Check it out - I like this worksheet and think it will work pretty well, even though everything in it looks very basic. We need to build sloooow conceptual understanding, and after that we will drill the rules using some games!
Addendum March 14, 2012: This lesson (parts 1 and 2) worked like a charm today!! I am feeling extremely positive about the outcome. The students could explain to me with NO PROBS WHATSOEVER why when you add or subtract terms with exponents, the resulting exponents don't change, but when you multiply them, they do change. My faster students were finished with the entire worksheet and did not have any misunderstanding at the end. They're ready for Phase 2: simplification drill games!!