Now I've had more than a month to think about things since my project ended, and other education-related events have kept me thinking about it (along with, of course, the necessity of finishing my blog record of my practice). So in the end, this is the advice I'd give to the students:
For math, science, etc.: Don't memorize the answers from the guides. Learn the material and the principles behind the material, and you will be able to solve any problem they throw at you. As an added bonus (though it should be the actual motivation), you'll actually be able to use your newfound skills in the real world, when there is no guidebook to give you answers.
For languages: Read. Next to living in a foreign country where you're immersed in the language, the best thing you can do to learn a language is read. It improves not only your vocabulary, but also your knowledge of sentence structures and idiomatic usage. With enough exposure, these things will get shoved into your subconscious mind, and creating your own sentences will be infinitely more easy.
In general: You all work very hard because you really want to learn. Keep that desire to learn, because the number of things you don't know will always be greater than the number of things you do know. Work on being able to solve problems on your own, based on what you know. Even if you can't see the whole pathway to the solution, do what you know, and see if that gets you anywhere.
The system beats creativity out of you, but always try to draw your own links and figure out how everything is connected. Place what you learn into context with what you've learned in other subjects. Make the information you're learning real for yourself.