The rule was never sleep without giving your brain something to work on. I spent an hour in the morning and an hour at night practicing the precise pronounciation of syllables, words and phrases, using tapes as a reference. There was little improvement during sessions, but noticeable improvement between them. Thus the rule about sleep.
As my pronunciation improved, so did my comprehension. I can't imagine it working the other way. Comprehension is passive, and no guarantee of accurate or even coherent production.
Following such a method you can learn a language in 6-12 months.
EDIT: I just read up on Krashen, and well, no, his theories are wrong. I wasted years on that crap. I doubt fluency is even possible with such a method. Just do what sounddust said and you'll be set.
EDIT2: The average person acquires fluency despite the Krashen method, rather than because of it. In my case, due to very poor audio recall, the Krashen method was a complete failure, so I was forced to experiment with other ways.
It turns out perception of foreign sounds is very weak in adults. We recognize a subset of possible sounds and toss out the rest, or munge it into something heavily accented. The repetition & production method compensates for this by making such sounds "real". Once they are real, the actual language follows more quickly.
EDIT3 (sorry): More on Krashen, from http://www.sk.com.br/sk-krash.html:
The only instance in which the teaching of grammar can result in language acquisition (and proficiency) is when the students are interested in the subject and _the target language_ is used as a medium of instruction.
This is so fucking wrong. The study of grammar is analytical. Language is the vehicle of analytic thought--if your proficiency in a language is weak, your level of analytic thought in that language is also weak. So if you want to study French grammar and you've only just started learning the language, by all means, study it in English.
Wow. So this is why the English-speaking world can't seem to learn a foreign language. Thank you xccx, you opened my eyes.