On a website I came across today, there’s some useful and interesting advice about studying languages. The author of the site, Alexander Arguelles, is a professor of linguistics and has studied many many languages – you can find out which ones on the how to learn any language forum.
There’s also some discussion of polyglottery, which is described as “a quest to develop an encyclopedic mind and to philosophically understand the nature of your own consciousness through the passionate, in-depth, and respectful study of as many different languages as possible, focusing both upon their diachronic evolution of as actual entities and upon the intellectual heritage they have left in the form of great texts”.
Prof. Arguelles has plans to set up a foreign language academy where he will teach people how to teach themselves languages. His methods include shadowing, which involves listening to a foreign language and repeating what you hear in a loud, clear voice while walking outdoors as swiftly as possible and maintaining a perfectly upright posture. There are videos explaining this and other methods on the language study section of the site.