For me, buying a bunch of books and spending hours learning vocabulary is not nearly as productive as logging in here, finding somebody who speaks the language I want to learn (Latin American Spanish, in my case) and talking with them face to face. Once I got away from making it an academic thing and started to actually USE the language, my progress became much more tangible and rapid. It’s important to know grammar, sentence structure and the other building blocks of the language but if you don’t spend the time learning the language as it’s actually spoken (with all of its grammatical inconsistencies, etc.) then what’s the point?