Look into some of the accelerated learning stuff:
Accelerated language learning - Wikipedia, the free encyclopedia
I can't attest to how well it works myself, but apparently this Georgi Lozanov fellow found a way for people to learn hundreds-thousands of language words per day, with 95% retention after a month or something crazy like that. Not bad, eh?
A lot of it seems to be based on using left-right brain synchronization by incorporating logical/linear along with visual/auditory, and relaxing the mind into the alpha brain wave state, which allows for optimal learning. So perhaps you can fiddle around with these things too.