No matter how many different classes require a paper to be written, always write one paper and reuse it for all classes. US Profs love creativity and when you come to them and ask if you can write about the "History of Religion" for your history paper they will always say yes. Then go to your religion professor and pitch the same paper. Et viola. Two classes with one paper. And since you'll have a little more time to write the one paper it will usually be better.

Also, always do the readings _before_ the class, not after. By offsetting your reading one week sooner then everyone else you'll have an advantage.