There all sorts of theories around how best to acquire a second language. Some people think you should dive right in and speak from day one. Other people think that it is perfectly normal for you to shut up and listen. There are polyglots who swear by translation as an aid for learning. There are others who think translation is the enemy of second-language acquisition. The point here is not that there are no rules. There clearly are--virtually everyone agrees, for instance, that immersion beats everything. (Which is sort of why you see "immersion" labels on products and classes that clearly are not.) And virtually everyone agrees, all things being equal, that it's easier to pick up a third and fourth language, than a second--mostly because having done it before, you have some idea how your brain works.
I use a product called Fluenz. I also use Anki to increase my vocabulary. There's a theory that holds that if you learn 3,000 words of your target language you will know about 95 percent of all the words used in a regular conversation. Also this summer, I took about four hours of class four to five times a week. Those classes were heavy on grammar. I have reservations about all of this. I'm skeptical of the idea that you can "know" a word without repeated exposure to it in different contexts. I have strong doubts about repetitive grammar exercises, and classes where the students don't talk a lot. But I also think those doubts aren't very important, because I enjoy making flashcards, my classes anchor my day, and Fluenz is a nice change of pace.
Am I learning at the optimal pace? Beats me. "Learning" is such a black box. We generally know that some people have more aptitude than others. We also generally agree that everyone should regularly practice. But after that there just seems to be a lot of grey area. In talking to people who've tried to learn a language and quit, I've come to believe that nailing the optimal method is not as important as continuing to put one foot in front of the other. In other words, I think, above all, you've got to find some method that keeps you practicing regularly over a long period of time.
And you've just have to wait. I'm talking to myself, more than I'm talking to you. Peregrin Coates wants "the French" right now and I wants it all. For those of us who can't afford immersion, everything happens so slow and the benchmarks are weird. I know that when I first started I couldn't say anything beyond "Bonjour" or "Merci" and I could not say them right. Now I can generally communicate with someone, who is trying to communicate with me--but they have to be trying and I have to tell myself "OK, we're speaking French right now." Some day I hope for things to be better. But the only way to really do that is to keep walking. You can't much think about the destination. You must focus on walking the path, and try not think about seeing it.