Most people are familiar with Duolingo. It's a cool program that gamifys language learning by using experience points and in game currency like lingots.
While Duolingo is fun and super-addicting it will only get you through the beginner level of a language. If you want to get to an intermediate level of study you need to suppliment your study with textbooks and listening exercises.
So what i usually do is finish the duolingo tree over the course of a week. Then i sign up for a LingQ account where i can read hundreds of audiobooks in my new language. The amazing thing about lingQ is it keeps track of any words you don't know, it makes me learn at blazing fast speeds:D
If you are using any other kind of language learning techniques please let me know and we can discuss some more.