Without some sort of course to start out with you can easily get lost, especially if you do not already know how to teach yourself things such as languages. Someone starting out with their first language probably will need a bit of direction in order to know what to do. When you get to your fourth, fifth, tenth, usually you know what you need yourself. I only use courses as long as it is absolutely necessary. I don't even remember doing a whole lot of lessons for Russian. 16 Assimil lessons was as far as I got before boredom struck. I managed rather good on my own though, in my opinion. I believe that what you need (or can use) to learn a language is:
- A reference grammar (a grammar with exercises is also great)
- Native material of varying difficulty (Easy Readers, articles, books)
- ANKI (or similar)
- Audio input (radio, audio books)
- A platform for writing (lang-8.com, pen pals)
Writing takes practice (and IRC or MSN is not the same thing, it's merely pseudo-writing, unstructured and spontaneous). When speaking French or Hungarian you can miss every other accent acute or perhaps mix up ü and ű and people will either not notice much or write it off as being your accent. When you write, and all of a sudden you show that you have no clue as to how to spell the French verb conjugations cause you learnt all your French from Pimsleur and MT, it will all of a sudden be a much bigger deal. Also, when you are writing things that are of concern to YOU, you become aware of what words and grammatical structures you frequently need. It isn't necessarily the same bunch of phrases TY teaches you.
I plan to try my own plan for Hungarian this summer. I have completed 44 Assimil lessons so far, and while I want to try to complete the course (as an experiment) I am going to try to use literature an LR rather intensively (Jane Eyre is first up!).