"nothing beats the intense language study at the HS level."
Except going and living in a country where they speak that language and very little English. There is nothing like a long haired dictionary, in my experience. It is all a matter of motivation.
But a solid educational preparation should be made beforehand.
I encourage every student to take at least three years, not just the required two, in a foreign language. If for no other reason, it looks great on your college application, when you take more than the required minimum.