Writer's block comes in two forms for me. There's the "I don't know where the story is going at all" version, and the "I don't like the way the words come out" version. The latter is easier to get through than the first.
With that version, the only way to get through it is to just keep writing. Sure, the words might sound terrible, but each word that is written is one more word than there was before. Besides, getting the words to sound better is what editing is for.
If it's the first version of writer's block, then all that I do is work on other stories. I've written whole entire multi-chaptered fics and even just some small scenes I've been sitting on because I don't know what to write next for the current project. I'm still writing, because I feel like some writing should be done every day (when possible). But this gives my mind a break from my current project, and I find that all of a sudden, I get that little bit of inspiration to head back to my current project and continue.