How do you actually expand your vocabulary?
I think I've reached a strange point where my grammar is okay. I can make sentences, conjugate most things, and handle tenses well. But when I try to say something, I just don't know the word. I know exactly how to say what I want to say, but I keep using the same 500 words over and over. It's annoying because the grammar isn't the problem anymore; it's the words. I've used flashcards, but after a week, I forget everything. Reading helps a little, but it takes a long time. It's nice to watch things in French, but I don't really learn new words; I just passively understand.
For those of you who were able to move past the intermediate plateau in your vocabulary, what worked? Did it just happen over time, or did you do something special?